Justinian II (Greek: Ιουστινιανός Β΄, Ioustinianos II, Latin: Justinianus II) (669 – 11 December 711), surnamed the Rhinotmetos or Rhinotmetus (ὁ Ῥινότμητος, "the slit-nosed"), was the last Byzantine Emperor of the Heraclian Dynasty, reigning from 685 to 695 and again from 705 to 711. Justinian II was an ambitious and passionate ruler who was keen to restore the Empire to its former glories, but he responded poorly to any opposition to his will and lacked the finesse of his father, Constantine IV. Consequently, he generated enormous opposition to his reign, and it resulted in his deposition in 695 in a popular uprising, and he only returned to the throne in 705 with the help of a Bulgar and Slav army. His second reign was even more despotic than the first, and it too saw his eventual overthrow in 711, abandoned by his army who turned on him before killing him.

Justinian II was the eldest son of Emperor Constantine IV and Anastasia. His father raised him to the throne as joint emperor in 681 on the fall of his uncles Heraclius and Tiberius. In 685, at the age of sixteen, Justinian II succeeded his father as sole emperor.

Justinian I ( /dʒʌˈstɪniən/) (Latin: Flavius Petrus Sabbatius Iustinianus Augustus, Ancient Greek: Φλάβιος Πέτρος Σαββάτιος Ἰουστινιανός) (c. 482 – 14 November 565), commonly known as Justinian the Great, was Byzantine Emperor from 527 to 565. During his reign, Justinian sought to revive the Empire's greatness and reconquer the lost western half of the classical Roman Empire.

One of the most important figures of Late Antiquity and the last Roman Emperor to speak Latin as a first language, Justinian's rule constitutes a distinct epoch in the history of the Eastern Roman Empire. The impact of his administration extended far beyond the boundaries of his time and domain. Justinian's reign is marked by the ambitious but only partly realized renovatio imperii, or "restoration of the Empire". This ambition was expressed by the partial recovery of the territories of the defunct Western Roman Empire. His general Belisarius swiftly conquered the Vandal Kingdom in North Africa, extending Roman control to the Atlantic Ocean. Subsequently Belisarius, Narses, and other generals conquered the Ostrogothic Kingdom, restoring Dalmatia, Sicily, Italy, and Rome to the Empire after more than half a century of barbarian control.