Agrippina the Younger
Agrippina, mother of Nero
Empress consort of the Roman Empire
Tenure	1 January AD 49 – 13 October AD 54 (&100000000000000050000005 years, &10000000000000285000000285 days)
Spouse	Gnaeus Domitius Ahenobarbus Gaius Sallustius Crispus Passienus Claudius
Issue
Nero, Emperor of Rome
House	Julio-Claudian Dynasty
Father	Germanicus
Mother	Agrippina the Elder
Born	7 November AD 15 Oppidum Ubiorum (Cologne)
Died	23 March AD 59 (aged 43) Misenum
Burial	Misenum

Julia Agrippina, most commonly referred to as Agrippina Minor or Agrippina the Younger, and after 50 known as Julia Augusta Agrippina (Minor Latin for the ‘younger’, Classical Latin: IVLIA•AGRIPPINA; IVLIA•AVGVSTA•AGRIPPINA,^[1] 7 November 15 or 6 November 16^[2] – 19/23 March 59) was a Roman Empress and one of the more prominent women in the Julio-Claudian dynasty. She was a great-granddaughter of the Emperor Augustus, great-niece and adoptive granddaughter of the Emperor Tiberius, sister of the Emperor Caligula, niece and fourth wife of the Emperor Claudius, and mother of the Emperor Nero.

Agrippina the Younger has been described by both the ancient and modern sources as ‘ruthless, ambitious, violent and domineering’. She was a beautiful and reputable woman and according to Pliny the Elder, she had a double canine in her upper right jaw, a sign of good fortune. Many ancient historians accuse Agrippina of poisoning Emperor Claudius, though accounts vary.^[3]

Family[link]

Agrippina was the first daughter and fourth living child of Agrippina the Elder and Germanicus. She had three elder brothers, Nero Caesar, Drusus Caesar and the future Emperor Caligula, and two younger sisters, Julia Drusilla and Julia Livilla. Agrippina's two elder brothers and her mother were victims of the intrigues of the Praetorian Prefect Lucius Aelius Sejanus.

She was the namesake of her mother. Agrippina the Elder was remembered as a modest and heroic matron, who was the second daughter and fourth child of Julia the Elder and the statesman Marcus Vipsanius Agrippa. The father of Julia the Elder was the Emperor Augustus, and Julia was his only natural child from his second marriage to Scribonia, who had close blood relations with Pompey the Great and Lucius Cornelius Sulla. Maternally, Agrippina descended directly from Augustus.

Germanicus, Agrippina's father, was a very popular general and politician. His mother was Antonia Minor and his father was the general Nero Claudius Drusus. He was Antonia Minor's first child. Germanicus had two younger siblings; a sister, named Livilla, and a brother, the future Emperor Claudius. Claudius was Agrippina's paternal uncle and third husband.

Antonia Minor was a daughter to Octavia the Younger by her second marriage to triumvir Mark Antony, and Octavia was the second eldest sister and full-blooded sister of Augustus. Germanicus’ father, Drusus the Elder, was the second son of the Empress Livia Drusilla by her first marriage to praetor Tiberius Nero, and was the Emperor Tiberius’s younger brother and Augustus’s stepson. In the year 9, Augustus ordered and forced Tiberius to adopt Germanicus, who happened to be Tiberius's nephew, as his son and heir. Germanicus was a favorite of his great-uncle Augustus, who hoped that Germanicus would succeed his uncle Tiberius, who was Augustus's own adopted son and heir. This in turn meant that Tiberius was also Agrippina's adoptive grandfather in addition to her paternal great-uncle.

Birth and early life[link]

Agrippina was born at Oppidum Ubiorum, a Roman outpost on the Rhine River located in present day Cologne, Germany. As a small child, she travelled with her parents throughout the Empire until she and her siblings (apart from Caligula) returned to Rome to live with and be raised by Antonia. Her parents, in the meantime, journeyed to Syria to complete official duties. One year later in October, Germanicus died suddenly in Antioch (modern Antakya, Turkey).

Germanicus’ death in the year 19 caused much public grief in Rome, and gave rise to rumors that he had been murdered by Gnaeus Calpurnius Piso and Munatia Plancina on the orders of Tiberius, as his widow Agrippina the Elder returned to Rome with his ashes. Agrippina the Younger was thereafter supervised by her mother, her paternal grandmother Antonia Minor, and her great-grandmother, Livia, all of them notable, influential, and powerful figures from whom she learnt how to survive. She lived on the Palatine Hill in Rome. Her great-uncle Tiberius had already become emperor and the head of the family after the death of Augustus in 14.

First marriage to Gnaeus Domitius Ahenobarbus[link]

After her thirteenth birthday in 28, Tiberius arranged for Agrippina to marry her paternal second cousin Gnaeus Domitius Ahenobarbus and ordered the marriage to be celebrated in Rome. Domitius came from a distinguished family of consular rank. Through his mother Antonia Major, Domitius was a great nephew of Augustus, first cousin to Claudius, and second cousin to Agrippina and Caligula. He had two sisters; Domitia Lepida the Elder and Domitia Lepida the Younger. Domitia Lepida the Younger was the mother of the Empress Valeria Messalina.

Antonia Major was the elder sister to Antonia Minor, and the first daughter of Octavia Minor and Mark Antony. According to Suetonius, Domitius was a wealthy man with a despicable and dishonest character, who, according to Suetonius, was “A man who was in every aspect of his life detestable," and served as consul in 32. Agrippina and Domitius lived between Antium (Anzio) and Rome. Not much is known about the relationship between them.

Reign of Caligula[link]

This unreferenced section requires citations to ensure verifiability.

During the reign of Caligula, coins like the one pictured here were issued depicting his three sisters, Drusilla, Livilla and Agrippina the Younger.

Tiberius died on March 16, 37 and Agrippina's only surviving brother, Caligula, became the new emperor. Being the emperor's sister gave Agrippina some influence.

Agrippina and her younger sisters Julia Drusilla and Julia Livilla received various honors from their brother, which included but were not limited to:

• They were given the rights of the Vestal Virgins like the freedom to view public games from the upper seats in the stadium.
• Coins were issued depicting images of Caligula and his sisters. Roman coins like these were never issued beforehand. The coins depicted Caligula on one side and his sisters on the opposite.
• Caligula added his sister's names in to motions. In loyalty oaths, it was, "I will not value my life or that of my children less highly than I do the safety of the Emperor and his sisters," or, if in consular motions: "Good fortune attend to the Emperor and his sisters."

Around the time that Tiberius died, Agrippina had become pregnant. Domitius had acknowledged the paternity of the child. In the early morning hours in Antium of December 15, 37, Agrippina gave birth to a son. Agrippina and Domitius named their son Lucius Domitius Ahenobarbus, after the Domitius' recently deceased father. This child would grow up to become the Emperor Nero. Nero was Agrippina's only natural child. Suetonius states that Domitius was congratulated by friends on the birth of his son, whereupon he replied "I don't think anything produced by me and Agrippina could possibly be good for the state or the people".

Caligula and his sisters were accused of having incestuous relationships. On June 10, 38, Drusilla died, possibly of a fever, rampant in Rome at the time. He was particularly fond of Drusilla, claiming to treat her as he would his own wife, even though Drusilla had a husband. Following her death, Caligula's relationship with Agrippina and Livilla changed, showing no special love or respect toward them after Drusilla's death. After this point, he was said to have gone insane.

In 39, Agrippina and Livilla, with their maternal cousin, Drusilla's widower Marcus Aemilius Lepidus, were involved in a failed plot to murder Caligula, a plot known as the Plot of the Three Daggers, which was to make Lepidus the new emperor. Lepidus, Agrippina and Livilla were accused of being lovers. Not much is known concerning this plot and the reasons behind it. At the trial of Lepidus, Caligula felt no compunction about denouncing them as adulteresses, producing handwritten letters discussing how they were going to kill him.

Exile[link]

Lepidus was executed. Agrippina and Livilla were exiled by their brother to the Pontine Islands. Caligula sold their furniture, jewellery, slaves and freedmen. In January 40, Domitius died of edema (dropsy) at Pyrgi. Lucius had gone to live with his second paternal aunt Domitia Lepida the Younger after Caligula had taken his inheritance away from him.

Caligula, his wife Milonia Caesonia and their daughter Julia Drusilla were murdered on January 24, 41. Agrippina's paternal uncle, Claudius, brother of her father Germanicus, became the new Roman Emperor.

Reign of Claudius[link]

Return from exile[link]

Messalina holding her son Britannicus, Louvre.

Claudius lifted the exiles of Agrippina and Livilla. Livilla returned to her husband, while Agrippina was reunited with her estranged son. After the death of her first husband, Agrippina tried to make shameless advances to the future emperor Galba, who showed no interest in her and was devoted to his wife Aemilia Lepida. On one occasion, Galba's mother-in-law gave Agrippina, in a whole bevy of married women, a public reprimand and a slap in the face.^[4]

Claudius had Lucius' inheritance reinstated. Lucius became more wealthy despite his youth shortly after. Gaius Sallustius Crispus Passienus divorced Lucius' aunt, Domitia Lepida the Elder (Lucius' first paternal aunt) so that Crispus could marry Agrippina. They married, and Crispus he became a step-father to Lucius. Crispus was a prominent, influential, witty, wealthy and powerful man, who served twice as consul. He was the adopted grandson and biological great, great nephew of the historian Sallust. Little is known on their relationship, but Crispus soon died and left his estate to Nero.

In the first years of Claudius’ reign, Claudius was married to the infamous Empress Valeria Messalina. Although Agrippina was very influential, she kept a very low profile and stayed away from the imperial palace and the court of the emperor. Messalina was Agrippina’s second paternal cousin. Among the victims of Messalina's intrigues were Agrippina's surviving sister Livilla, who was charged with having adultery with Seneca the Younger. Seneca was later called back from exile to be a tutor to Nero.

Messalina considered Agrippina’s son a threat to her son’s position and sent assassins to strangle Lucius during his siesta. The assassins left in terror because a snake suddenly darted from beneath Lucius’ pillow—but it was only a sloughed-off snake-skin in his bed, near his pillow.

In 47, Crispus died, and at his funeral, the rumor spread around that Agrippina poisoned Crispus to gain his estate. After being widowed a second time, Agrippina was left very wealthy. Later that year at the Secular Games, at the performance of the Troy Pageant, Messalina attended the event with her son Britannicus. Agrippina was also present with Lucius. Agrippina and Lucius received greater applause from the audience than Messalina and Britannicus did. Many people began to show pity and sympathy to Agrippina, due to the unfortunate circumstances in her life. Agrippina wrote a memoir that recorded the misfortunes of her family (casus suorum) and wrote an account of her mother’s life.

Rise to power[link]

After Messalina was executed in 48 for conspiring with Gaius Silius to overthrow her husband, Claudius considered remarrying for the fourth time. Around this time, Agrippina became the mistress to one of Claudius’ advisers, the former Greek Freedman Marcus Antonius Pallas. At that time Claudius’ advisers were discussing which noblewoman Claudius should marry. Claudius had a reputation that he was easily controlled by his wives and freedmen. His freedmen, according to legend, presented him three possible candidates.

The freedman Tiberius Claudius Narcissus suggested Claudius remarry his second wife Aelia Paetina, with whom he had a daughter, Claudia Antonia. Narcissus also stated that Paetina would cherish Claudia Octavia and Britannicus, Claudius's children with Messalina.

Another freedman, Gaius Julius Callistus, was against Claudius remarrying Paetina and stated to Claudius that he divorced her before and that remarrying Paetina would make her more arrogant. Callistus suggested Lollia Paulina, Caligula's third wife and Agrippina's former sister-in-law instead.

Pallas advised Claudius that he should marry Agrippina. Pallas stated to the emperor that as Lucius was the grandson to Claudius's late brother Germanicus, by marrying Agrippina, Claudius would ally the two branches of the Claudian house and imperial family. In more recent times, it has been suggested that the Senate may have pushed for the marriage between Agrippina and Claudius to end the feud between the Julian and Claudian branches.^[5] This feud dated back to Agrippina's mother's actions against Tiberius after the death of Germanicus, actions which Tiberius had gladly punished.

Regardless, for Agrippina’s seduction, it was a help that she had the niece’s privilege of kissing and caressing her paternal uncle. Claudius was seduced by her passions. Claudius made references to her in his speeches: "my daughter and foster child, born and bred, in my lap, so to speak". When Claudius decided to marry her, he persuaded a group of senators that the marriage should be arranged in the public interest. In Roman society, an uncle (Claudius) marrying his niece (Agrippina) was considered incestuous, and obviously immoral.

Marriage to Claudius[link]

Agrippina and Claudius married on New Year’s Day, 49. This marriage caused widespread disapproval. This was a part of Agrippina’s scheming plan to make Lucius the new emperor. Her marriage to Claudius was not based on love, but on power. She quickly eliminated her rival Lollia Paulina. In 49, shortly after marrying Claudius, Agrippina charged Paulina with black magic. Paulina did not receive a hearing. Her property was confiscated, she left Italy and on Agrippina's orders, she committed suicide.

In the months leading up to her marriage to Claudius, Agrippina's maternal second cousin, the praetor Lucius Junius Silanus Torquatus, was betrothed to Claudius’ daughter Claudia Octavia. This betrothal was broken off in 48 when Agrippina, scheming with the consul Lucius Vitellius the Elder, the father of the future Emperor Aulus Vitellius, falsely accused Silanus of incest with his sister Junia Calvina. Agrippina did this hoping to secure a marriage between Octavia and her son. Consequently, Claudius broke off the engagement and forced Silanus to resign from public office.

Silanus committed suicide on the day that Agrippina married her uncle, and Calvina was exiled from Italy in early 49. Calvina was called back from exile after the death of Agrippina. Towards the end of 54, Agrippina would order the murder of Silanus' eldest brother Marcus Junius Silanus Torquatus without Nero's knowledge, so that he would not seek revenge against her over his brother's death.

Empress of Rome[link]

Roman aureus depicting Agrippina and Claudius, c. 50/54

On the day that Agrippina married her uncle Claudius as her third husband/his fourth wife, she became an Empress and the most powerful woman in the Roman Empire. She also was a stepmother to Claudia Antonia, Claudius' daughter and only child from his second marriage to Aelia Paetina, and to the young Claudia Octavia and Britannicus, Claudius' children with Valeria Messalina. Agrippina removed or eliminated anyone from the palace or the imperial court who she thought was loyal and dedicated to the memory of the late Messalina. She also eliminated or removed anyone who she considered was a potential threat to her position and the future of her son, one of her victims being Lucius' second paternal aunt and Messalina's mother Domitia Lepida the Younger.

In 49, Agrippina presided over the exercises of Roman legions. The Celtic King Caratacus assumed that she, along with Claudius, was the martial leader and bowed before her throne with the same homage and gratitude as he accorded the emperor. In 50, Agrippina was granted the honorific title of Augusta, a title which, up until this point, no other imperial woman had ever received in the lifetime of her husband. She was only the third Roman woman (Livia Drusilla and Antonia Minor received this title) and only the second living Roman woman (the first being Livia) to receive this title.

Also that year, Claudius had founded a Roman colony and called the colony Colonia Claudia Ara Agrippinensis or Agrippinensium, today known as Cologne, after Agrippina who was born there. This colony was the only Roman colony to be named after a Roman woman. In 51, she was given a carpentum which she used. A carpentum was a sort of ceremonial carriage usually reserved for priests, such as the Vestal Virgins, and sacred statues. That same year she appointed Sextus Afranius Burrus as the head of the Praetorian Guard, replacing the previous head of the Praetorian Guard, Rufrius Crispinus.

Agrippina successfully manipulated and influenced Claudius into adopting her son and having him become his successor. Lucius Domitius Ahenobarbus in 50 was adopted by his great maternal uncle and stepfather. Lucius’ name was changed to Nero Claudius Caesar Drusus Germanicus and he became Claudius’s adopted son, heir and recognised successor. Agrippina and Claudius betrothed Nero to Octavia, and Agrippina arranged to have Seneca the Younger return from exile to tutor the future emperor. Claudius chose to adopt Nero because of his Julian and Claudian lineage.^[6]

Agrippina deprived Britannicus of his heritage and further isolated him from his father and succession for the throne in every way possible. For instance, in 51, Agrippina ordered the execution of Britannicus’ tutor Sosibius because he had confronted her and was outraged by Claudius’ adoption of Nero and his choice of Nero as successor, instead of choosing his own son Britannicus.^[7]

Nero and Octavia were married on June 9, 53. Claudius later repented of marrying Agrippina and adopting Nero, began to favor Britannicus, and started preparing him for the throne. His actions allegedly gave Agrippina a motive to eliminate Claudius. The ancient sources say she poisoned Claudius on October 13, 54 with a plate of deadly mushrooms at a banquet, thus enabling Nero to quickly take the throne as emperor. Accounts vary wildly with regard to this private incident and according to more modern sources, it is possible (but exceedingly convenient) that Claudius died of natural causes; Claudius was 63 years old.^[3]

Reign of Nero[link]

Power struggle between mother and son[link]

Sculpture of Agrippina crowning her young son Nero (ca. 54-59 AD).

Marble bust of Nero. Antiquarium of the Palatine.

Agrippina was named a priestess of the cult of the deified Claudius. She was allowed to visit senate meetings, watch and hear the meetings behind a curtain. This evidently shows that she had real power.

In the first months of Nero’s reign Agrippina controlled her son and the Empire. She lost control over Nero when he began to have an affair with the freedwoman Claudia Acte, which Agrippina strongly disapproved of and violently scolded him for. Agrippina began to support Britannicus in her attempt to make him emperor. Britannicus was secretly poisoned on Nero’s orders during a banquet in February 55. The power struggle between Agrippina and her son had begun.

Agrippina between 55 and 58 became very watchful and had a critical eye over her son. In 55, Agrippina was forced out of the palace by her son to live in imperial residence. Nero deprived his mother of all honors and powers, and even removed her Roman and German bodyguards. Nero even threatened his mother he would abdicate the throne and would go to live on the Greek Island of Rhodes, a place where Tiberius had lived after divorcing Julia the Elder. Pallas also was dismissed from the court. The fall of Pallas and the opposition of Burrus and Seneca, contributed to Agrippina's loss of authority.^[8]

Towards 57, Agrippina was expelled from the palace and went to live in a riverside estate in Misenum. While Agrippina lived there or when she went on short visits to Rome, Nero had sent people to annoy her. Although living in Misenum, she was still very popular, powerful and influential. Agrippina and Nero would see each other on short visits.

Death and aftermath[link]

The circumstances that surround Agrippina's death are uncertain due to historical contradictions and anti-Nero bias. All surviving stories of Agrippina's death contradict themselves and each other, and are generally fantastical.

Tacitus's account[link]

According to Tacitus, in 58, Nero became involved with the noble woman Poppaea Sabina. With the reasoning that a divorce from Octavia and a marriage to Poppaea was not politically feasible with Agrippina alive, Nero decided to kill Agrippina.^[9] Yet, Nero did not marry Poppaea until 62, calling into question this motive.^[10] Additionally, Suetonius reveals that Poppaea's husband, Otho, was not sent away by Nero until after Agrippina's death in 59, making it highly unlikely that already married Poppaea would be pressing Nero.^[11] Some modern historians theorize that Nero's decision to kill Agrippina was prompted by her plotting to set Gaius Rubellius Plautus (Nero's maternal second cousin) or Britannicus (Claudius' biological son) on the throne.^[12]

Tacitus claims that Nero considered poisoning or stabbing her, but felt these methods were too difficult and suspicious, so he settled on building a self-sinking boat.^[13] Though aware of the plot, Agrippina embarked on this boat and was nearly crushed by a collapsing lead ceiling only to be saved by the side of a sofa breaking the ceiling's fall.^[14] Though the collapsing ceiling missed Agrippina, it crushed her attendant who was outside by the helm.^[14]

The boat failed to sink from the lead ceiling, so the crew then sank the boat, but Agrippina swam to shore.^[14] Her friend, Acerronia Polla, was attacked by oarsmen while still in the water, and was either bludgeoned to death or drowned, since she was exclaiming that she was Agrippina, with the intention of being saved, unfortunately she did not know that this was an attempt of Agrippina's life, not a mere accident. Agrippina was met at the shore by crowds of admirers.^[15] News of Agrippina's survival reached Nero so he sent three assassins to kill her.^[15]

Suetonius's account[link]

According to Suetonius, Nero was annoyed at his mother being too watchful and tried three times to poison Agrippina, but she took the antidotes in time and survived.^[16] He then tried to crush her with a mechanical ceiling over her bed at her residence.^[16] After this failed, he devised a collapsable boat, which would either have its cabin fall in or become shipwrecked. Nero then ordered captains of a different boat to ram this boat while Agrippina was aboard.^[16] Nero heard Agrippina survived the wreck so he ordered her to be executed and framed it as a suicide.^[16]

Cassius Dio's account[link]

The tale of Cassius Dio is also somewhat different. It starts again with Poppaea as the motive behind the murder.^[17] Nero designed a ship that would open at the bottom while at sea.^[18] Agrippina was put aboard and after the bottom of the ship opened up, she fell into the water.^[18] Agrippina swam to shore so Nero sent an assassin to kill her.^[19] Nero then claimed Agrippina plotted to kill him and committed suicide.^[20] Her reputed last words, uttered as the assassin was about to strike, were "Smite my womb", the implication here being she wished to be destroyed first in that part of her body that had given birth to so "abominable a son."^[21]

Burial[link]

After Agrippina's death, Nero viewed her corpse and commented how beautiful she was, according to some.^[22] Her body was cremated that night on a dining couch. At his mother's funeral, Nero was witless, speechless and rather scared. When the news spread that Agrippina had died, the Roman army, senate and various people sent him letters of congratulations that he had murdered his mother.

Aftermath[link]

During the remainder of Nero's reign, Agrippina's grave was not covered or enclosed. Her household later on gave her a modest tomb in Misenum. Nero would have his mother’s death on his conscience. He felt so guilty he would sometimes have nightmares about his mother. He even saw his mother’s ghost and got Persian magicians to scare her away. Years before she died, Agrippina had visited astrologers to ask about her son’s future. The astrologers had rather accurately predicted that her son would become emperor and would kill her. She replied, "Let him kill me, provided he becomes emperor," according to Tacitus.

Agrippina's Lovers[link]

Gaius or Caligula- Agrippina's brother (Dio.)

Marcus Aemilius Lepidus -her sister Drusilla's husband (Tac. Suet. Dio)
Tigellinus- later prefect of the guard under Nero (Dio)
Lucius Annaeus Seneca -Nero’s tutor (Dio.Tac)
Claudius -her uncle before their marriage (Tac. Suet. Dio)
Rufus -later prefect of the guard (Tac)
Marcus Antonius Pallas -Claudius’ freedmen (Tac. Dio.)
Aulus Plautius -young nobleman (Suet.)
Rubellius Plautus- son of Julia, granddaughter of Tiberius (Tac.)
Nero -her son (Tac. Suet. Dio)

Agrippina's Victims[link]

47
1. Passienus Crispus Agrippina’s 2nd husband poisoned (suet.)

49
2. Lollia Paulina as she was a rival for Claudius’ hand in marriage as proposed by the freedman Callistus. (Tac. & Dio)
3. Lucius Silanus was betrothed to Octavia, Claudius’ daughter before his marriage of Agrippina. He committed suicide on their wedding day.
4. Sosibius Britannicus’ tutor executed for plotting against Nero
5. Calpurnia banished (Tac.) executed (Dio) because Claudius had commented on her beauty

53
6. Statilius Taurus was forced to suicide because Agrippina wanted his gardens (Tac.)

54
7. Claudius her husband poisoned (Tac. Sen. Juv. Suet. Dio.)
8. Domitia Lepida mother of Messalina executed (Tac.)
9. Marcus Junius Silanus potential rival to Nero poisoned (Pliny, Tac. Dio)
10. Cadius Rufus was executed on the charge of extortion

Ancestry[link]

In later literature[link]

The Empress, by Robert DeMaria, Vineyard Press (ISBN 1-930067-05-4)

Handel's 1709 opera, Agrippina with a libretto by Vincenzo Grimani.

In film[link]

Imperium: Nero 2005 Agrippina is played by Laura Morante

I, Claudius 1976 Agrippina is played by Barbara Young

A.D 1985 Miniseries Agrippina is played by Ava Gardner

Perspectives on Agrippina's personality[link]

Ancient[link]

• Note that most ancient Roman sources are quite critical of Agrippina the Younger, because she was seen as stepping outside the conservative Roman ideals regarding the roles of women in society.
• Tacitus: Critical view, considered her vicious and had a strong disposition against her due to her femininity and influential role in politics. Perhaps the most comprehensive of Ancient sources. Others are Suetonius and Cassius Dio.

Modern[link]

• E. Groag, A. Stein, L. Petersen – e.a. (edd.), Prosopographia Imperii Romani saeculi I, II et III, Berlin, 1933 –. (PIR²)
• Scullard: A critical view of Agrippina, suggesting she was ambitious and unscrupulous and a depraved sexual psychopath. "Agrippina struck down a series of victims; no man or woman was safe if she suspected rivalry or desired their wealth."^[23]
• Ferrero: Sympathetic and understanding, suggesting Agrippina has been judged harshly by history. Suggesting her marriage to Claudius was to a weak emperor who was, because of his hesitations and terrors, a threat to the imperial authority and government. She saw it her duty to compensate for the innumerable deficiencies of her strange husband through her own intelligence and strength of will. Pages 212ff.; 276ff.
• Barrett: A reasonable view, comparing Scullard's criticisms to Ferrero's apologies. (See Barrett, Anthony A., Agrippina: Sex, Power and Politics in the Early Roman Empire, Yale University Press, New Haven, 1996.)
• Annelise Freisenbruch "The first ladies of Rome"
• Wood, S. "Diva Drusilla Panthea and the Sisters of Caligula American Journal of Archaeology, Vol. 99, No. 3 (Jul., 1995)
• Rogers, R. S. The Conspiracy of Agrippina Transactions and Proceedings of the American Philological Association, Vol. 62 (1931)
• Godolphin, F. R. B. A Note on the Marriage of Claudius and Agrippina Classical Philology, Vol. 29, No. 2 (Apr., 1934)
• Grimm-Samuel, V On the Mushroom That Deified the Emperor Claudius The Classical Quarterly, New Series, Vol. 41, No. 1 (1991)
• McDaniel, W. B Bauli the Scene of the Murder of Agrippina The Classical Quarterly, Vol. 4, No. 2 (Apr., 1910)
• Salmonson, Jessica Amanda. (1991) The Encyclopedia of Amazons. Paragon House. Pages 4–5.
• Donna Hurley, Agrippina the Younger (Wife of Claudius).
• L. Foubert, Agrippina. Keizerin van Rome, Leuven, 2006.
• Opera by G.F. Händel: Agrippina

References[link]

Wikimedia Commons has media related to: Agrippina Minor

• Tacitus, Annales xii.1–10, 64–69, xiv.1–9
• Suetonius, De vita Caesarum – Claudius v.44 and Nero vi.5.3, 28.2, 34.1–4

Prussian blue
IUPAC name Iron(II,III) hexacyanoferrate(II,III)
Other names Berlin blue Ferric ferrocyanide Ferric hexacyanoferrate Iron(III) ferrocyanide Iron(III) hexacyanoferrate(II) Parisian blue
Identifiers
CAS number	14038-43-8 Y
PubChem	2724251
ChemSpider	20074656 Y
UNII	TLE294X33A Y
EC number	237-875-5
ChEBI	CHEBI:30069 Y
ChEMBL	CHEMBL1200325 N
RTECS number	V03AB31
Gmelin Reference	1093743
Jmol-3D images	Image 1
SMILES [Fe+3].[Fe+3].[Fe+3].[Fe+3].N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N.N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N.N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N
InChI InChI=1S/18CN.7Fe/c18*1-2;;;;;;;/q;;;;;;;;;;;;;;;;;;3*-4;4*+3 Y Key: DNMNDNSFJMUUFM-UHFFFAOYSA-N Y InChI=1S/18CN.7Fe/c18*1-2;;;;;;;/q;;;;;;;;;;;;;;;;;;3*-4;4*+3
Properties
Molecular formula	C18Fe7N18
Molar mass	859.23 g mol−1
Appearance	Blue opaque crystals
Pharmacology
Routes of administration	Oral
Hazards
MSDS	MSDS prussian blue
Related compounds
Other cations	Potassium ferrocyanide Sodium ferrocyanide
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa)
Infobox references

Prussian Blue
— Color coordinates —
Hex triplet		#003153
RGBB	(r, g, b)	(0, 49, 83)
HSV	(h, s, v)	(205°, 100%, 33%)
Source		[1]
B: Normalized to [0–255] (byte)

Prussian blue is a dark blue pigment with the idealized formula Fe₇(CN)₁₈. Another name for the color Prussian blue is Berlin blue or, in painting, Parisian blue. Turnbull's blue is the same substance but is made from different reagents.

Prussian blue was one of the first synthetic pigments. It is employed as a very fine colloidal dispersion, as the compound itself is not soluble in water. It is famously complex,^[1] owing to the presence of variable amounts of other ions and the sensitive dependence of its appearance on the size of the colloidal particles formed when it is made. The pigment is used in paints, and it is the traditional "blue" in blueprints.

In medicine, Prussian blue is used as an antidote for certain kinds of heavy metal poisoning (caesium and thallium).

Prussian blue lent its name to prussic acid, which was derived from it, and to ferrocyanide (originally meaning "blue compound of iron", from Latin ferrum and Greek κυανεος). As ferrocyanide is made of iron and CN ligands, reinterpreting the component "-cyanide" in the compound word, produced the word "cyanide" for compounds containing the CN radical.

History[link]

Prussian blue [Fe₄[Fe(CN)₆]₃] was probably synthesized for the first time by the paint maker Diesbach in Berlin around the year 1706.^[2] Most historical sources do not mention a first name of Diesbach. Only Berger refers to him as Johann Jacob Diesbach.^[3] It was named "Preußisch blau" and "Berlinisch Blau" in 1709 by its first trader.^[4] The pigment replaced the expensive Lapis lazuli and was an important topic in the letters exchanged between Johann Leonhard Frisch^[5] and the president of the Royal Academy of Sciences, Gottfried Wilhelm Leibniz, between 1708 and 1716.^[4] It is first mentioned in a letter written by Frisch to Leibniz, from March 31, 1708. Not later than 1708, Frisch began to promote and sell the pigment across Europe. By August 1709, the pigment had been termed "Preussisch blau"; by November 1709, the German name "Berlinisch Blau" had been used for the first time by Frisch. Frisch himself is the author of the first known publication of Prussian blue in the paper Notitia Coerulei Berolinensis nuper inventi in 1710, as can be deduced from his letters. Diesbach had been working for Frisch since about 1701.

In 1731, Georg Ernst Stahl published an account of the first synthesis of Prussian blue.^[6] The story involves not only Diesbach but also Johann Konrad Dippel. Diesbach was attempting to create a red lake pigment from cochineal but obtained the blue instead as a result of the contaminated potash he was using. He borrowed the potash from Dippel, who had used it to produce his "animal oil". No other known historical source mentions Dippel in this context. It is therefore difficult to judge the reliability of this story today. In 1724, the recipe was finally published by John Woodward.^[7][8][9]

To date, the "Entombment of Christ", dated 1709 by Pieter van der Werff (Picture Gallery, Sanssouci, Potsdam) is the oldest known painting where Prussian blue was used. Around 1710, painters at the Prussian court were already using the pigment. At around the same time, Prussian blue arrived in Paris, where Antoine Watteau and later his successors Nicolas Lancret and Jean-Baptiste Pater used it in their paintings.^[10]

"The Great Wave off Kanagawa" by Hokusai, a famous artwork which makes extensive use of Prussian blue.

This Prussian blue pigment is significant since it was the first stable and relatively lightfast blue pigment to be widely used following the loss of knowledge regarding the synthesis of Egyptian Blue. European painters had previously used a number of pigments such as indigo dye, smalt, and Tyrian purple, which tend to fade, and the extremely expensive ultramarine made from lapis lazuli. Japanese painters and woodblock print artists likewise did not have access to a long-lasting blue pigment until they began to import Prussian blue from Europe.

In 1752 the French chemist Pierre J. Macquer made the important step of showing the Prussian blue could be reduced to a salt of iron and a new acid, which could be used to reconstitute the dye.^[11] The new acid, hydrogen cyanide, first isolated from Prussian blue in pure form and characterized about 1783 by the Swedish chemist Carl Wilhelm Scheele, was eventually given the name Blausäure (literally "Blue acid") because of its derivation from Prussian blue, and in English became known popularly as Prussic acid. Prussian blue would also give the name to the ferrocyanide and cyanide family of compounds. Ferrocyanide (which is yellow) was coined as Neo Latin for "iron-containing blue material", since it was first isolated from Prussian blue. Cyanide, a colorless anion that forms in the process of making Prussian Blue, was named, in turn, for hydrogen cyanide (also colorless), and ultimately from ferrocyanide. It is for this reason that cyanide, even though the name of a colorless radical, is a Latinized form of the Greek word for "dark blue."

Production[link]

Prussian blue is produced by oxidation of ferrous ferrocyanide salts. These white solids have the formula M₂Fe[Fe(CN)₆] where M⁺ = Na⁺ or K⁺. The iron in this material is all ferrous, hence the absence of deep color associated with the mixed valency. Oxidation of this white solid with hydrogen peroxide or sodium chlorate produces ferricyanide and affords Prussian Blue.^[12]

A "soluble" form of PB, K[Fe^IIIFe^II(CN)₆], which is really colloidal, can be made from potassium ferrocyanide and iron(III):

K⁺ + Fe³⁺ + [Fe^II(CN)₆]^4- → KFe^III[Fe^II(CN)₆]

The similar reaction of potassium ferricyanide and iron(II) results in the same colloidal solution, because [Fe^III(CN)₆]^3- is converted into ferrocyanide.

"Insoluble" Prussian blue is produced if in the reactions above an excess of Fe³⁺ or Fe²⁺, respectively, is added.  In the first case:

4Fe³⁺ + 3[Fe^II(CN)₆]^4- → Fe^III[Fe^IIIFe^II(CN)₆]₃ ^[13]

"Turnbull's blue"[link]

Ferricyanide ion, used to make 'Turnbull's blue'.

In former times, it was thought that addition of Fe(II) salts to a solution of ferricyanide affords a material different from Prussian blue. The product was traditionally named "Turnbull's Blue" (TB). It has been shown, however, by means of X-ray diffraction and electron diffraction methods, that the structures of PB and TB are identical.^[14][15] The differences in the colors for TB and PB reflect subtle differences in the method of precipitation, which strongly affects particle size and impurity content.

Properties[link]

Prussian blue is a microcrystalline blue powder. It is insoluble, but the crystallites tend to form a colloid. Such colloids can pass through fine filters.^[1] Despite being one of the oldest known synthetic compounds, the composition of Prussian blue remained uncertain for many years. The precise identification of Prussian blue was complicated by three factors:

1. Prussian blue is extremely insoluble but also tends to form colloids;
2. Traditional syntheses tend to afford impure compositions;
3. Even pure Prussian blue is structurally complex, defying routine crystallographic analysis.

Crystal structure[link]

The chemical formula of insoluble Prussian blue is Fe₇(CN)₁₈·xH₂O, where x = 14–16. The structure was determined by using IR spectroscopy, Moessbauer spectroscopy, X-ray crystallography, and neutron crystallography. Since X-ray diffraction cannot distinguish carbon from nitrogen, the location of these lighter elements is deduced by spectroscopic means as well as by observing the distances from the iron atom centers.

PB has a cubic lattice structure. Soluble PB crystals contain interstitial K⁺ ions; insoluble PB has interstitial water instead.
In ideal insoluble PB crystals, the cubic framework is built from Fe(II)-C-N-Fe(III) sequences, with Fe(II)-carbon distances of 1.92 Ã… and Fe(III)-nitrogen distances of 2.03 Ã…. One-fourth of the sites of Fe(CN)₆ subunits are vacant (empty), leaving three such groups. The empty nitrogen sites are filled with water molecules instead, which are coordinated to Fe(III).

The Fe(II) centers, which are low spin, are surrounded by six carbon ligands in an octahedral configuration. The Fe(III) centers, which are high spin, are octahedrally surrounded on average by 4.5 nitrogen atoms and 1.5 oxygen atoms (the oxygen from the six coordinated water molecules). Additional eight (interstitial) water molecules are present in the unit cell, either as isolated molecules or hydrogen bonded to the coordinated water.

The composition is notoriously variable due to the presence of lattice defects, allowing it to be hydrated to various degrees as water molecules are incorporated into the structure to occupy cation vacancies. The variability of Prussian blue's composition is attributable to its low solubility, which leads to its rapid precipitation without the time to achieve full equilibrium between solid and liquid.^{[16] [17]}

Color[link]

Prussian blue is strongly colored and tends towards black and dark blue when mixed into oil paints. The exact hue depends on the method of preparation, which dictates the particle size. The intense blue color of Prussian blue is associated with the energy of the transfer of electrons from Fe(II) to Fe(III). Many such mixed-valence compounds absorb certain wavelengths of visible light resulting from intervalence charge transfer. In this case, orange-red light around 680 nanometers in wavelength is absorbed, and the reflected light appears blue as a result.

Like most high chroma pigments, Prussian blue cannot be accurately displayed on a computer display, but this swatch gives a common approximation, the sRGB colour #003153, intended for viewing on an output device with a gamma of 2.2^[18]:

_________

PB is electrochromic—changing from blue to colorless upon reduction. This change is caused by reduction of the Fe(III) to Fe(II) eliminating the intervalence charge transfer that causes Prussian blue's color.

Uses[link]

Pigment[link]

Because it is easily made, cheap, non-toxic, and intensely colored, Prussian blue has attracted many applications. The dominant uses are for pigments: approximately 12,000 tonnes of Prussian blue are produced annually for use in black and bluish inks. A variety of other pigments also contain the material.^[12] Engineer's blue and the pigment formed on cyanotypes—giving them their common name blueprints. Certain crayons were once colored with Prussian blue (later relabeled Midnight Blue). It is also a popular pigment in paints. Similarly, Prussian blue is the basis for laundry bluing.

Medicine[link]

Prussian blue's ability to incorporate monocations makes it useful as a sequestering agent for certain heavy metal poisons. Pharmaceutical-grade Prussian blue in particular is used for patients who have ingested thallium or radioactive caesium. According to the International Atomic Energy Agency, an adult male can eat at least 10 grams of Prussian blue per day without serious harm. The U.S. Food and Drug Administration (FDA) has determined that the "500 mg Prussian blue capsules, when manufactured under the conditions of an approved New Drug Application (NDA), can be found safe and effective therapy" in certain poisoning cases.^[19] Radiogardase (Prussian blue in soluble capsules ^[20]) is a commercial product for the removal of caesium-137 from the intestine and so indirectly from the bloodstream by intervening in the enterohepatic circulation of caesium-137,^[21] reducing the internal residency time (and exposure) by about two-thirds.

Laboratory histopathology stain for iron[link]

Prussian blue stain

Prussian blue is a common histopathology stain used by pathologists to detect the presence of iron in biopsy specimens, such as in bone marrow samples. The original stain formula, known historically (1867) as "Perls' Prussian blue" after its inventor, German pathologist Max Perls (1843–1881), used separate solutions of potassium ferrocyanide and acid to stain tissue (these are now used combined, just before staining). Iron deposits in tissue then form the purple Prussian blue dye in place, and are visualized as blue or purple deposits.^[22] The formula is also known as Perls Prussian blue and (incorrectly) as Perl's Prussian blue.

By machinists and toolmakers[link]

Prussian blue in oil paint is the traditional material used for spotting metal surfaces such as surface plates and bearings for hand scraping. A thin layer of non-drying paste is applied to a reference surface and transfers to the high spots of the workpiece. The toolmaker then scrapes, stones, or otherwise removes the marked high spots. Prussian blue is preferable because it will not abrade the extremely precise reference surfaces as many ground pigments may.

Analytical chemistry[link]

Prussian blue is formed in the Prussian blue assay for total phenols. Samples and phenolic standards are given acidic ferric chloride and ferricyanide which is reduced to ferrocyanide by the phenols. The ferric chloride and ferrocyanide react to form Prussian blue. Comparing the absorbance at 700 nm of the samples to the standards allows for the determination of total phenols.^[23]

Safety[link]

Despite the fact that it is prepared from cyanide salts, Prussian blue is nontoxic because the cyanide groups are tightly bound to Fe. Other polymeric cyanometalates are similarly stable with low toxicity.^{[citation needed]}

See also[link]

References[link]

External links[link]

• The FDA's page on prussian blue
• The CDC's page on prussian blue
• National Pollutant Inventory – Cyanide compounds fact sheet
• Heyltex Corporation distributors of Radiogardase (Prussian blue insoluble capsules)
• Sarah Lowengard, "Prussian Blue" in The Creation of Color in Eighteenth Century Europe Columbia University Press, 2006