The term Tetrarchy (Greek: "leadership of four [people]") describes any form of government where power is divided among four individuals, but in modern usage usually refers to the system instituted by Roman Emperor Diocletian in 293, marking the end of the Crisis of the Third Century and the recovery of the Roman Empire. This Tetrarchy lasted until c.313, when internecine conflict eliminated most of the claimants to power, leaving Constantine in the West and Licinius in the East.

Although the term "tetrarch" was current in antiquity, it was never used of the imperial college under Diocletian. Instead, the term was used to describe independent portions of a kingdom that were ruled under separate leaders. The tetrarchy of Judaea, established after the death of Herod the Great, is the most famous example of the antique tetrarchy. The term was understood in the Latin world as well, where Pliny the Elder glossed it as follows: "each is the equivalent of a kingdom, and also part of one" (regnorum instar singulae et in regna contribuuntur).

Leroy Anderson (June 29, 1908 – May 18, 1975) was an American composer of short, light concert pieces, many of which were introduced by the Boston Pops Orchestra under the direction of Arthur Fiedler. John Williams described him as "one of the great American masters of light orchestral music."

Born in Cambridge, Massachusetts to Swedish parents, Anderson was given his first piano lessons by his mother, who was a church organist. He continued studying piano at the New England Conservatory of Music. In 1925 Anderson entered Harvard University, where he studied theory with Walter Spalding, counterpoint with Edward Ballantine, harmony with George Enescu, composition with Walter Piston and double bass with Gaston Dufresne.^{[citation needed]} He also studied organ with Henry Gideon. He graduated with a Bachelor of Arts degree in 1929 and Master of Arts in 1930.

Anderson continued studying at Harvard, working towards a PhD in German and Scandinavian languages. (Anderson spoke English and Swedish during his youth but he eventually became fluent in Danish, Norwegian, Icelandic, German, French, Italian, and Portuguese.) During this time he was also working as organist and choir director at the East Milton Congregational Church, leading the Harvard University Band, and conducting and arranging for dance bands around Boston. His arranging work came to the attention of Arthur Fiedler in 1936 and Anderson was asked to show Fiedler any original compositions. Anderson's first work was Jazz Pizzicato in 1938. Fiedler suggested that a companion piece be written and thus Anderson wrote Jazz Legato in 1938.

Constantine the Great (Latin: Flavius Valerius Aurelius Constantinus Augustus; c. 27 February 272 – 22 May 337), also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all religions throughout the empire.

The foremost general of his time, Constantine defeated the emperors Maxentius and Licinius during civil wars. He also fought successfully against the Franks, Alamanni, Visigoths, and Sarmatians during his reign—even resettling parts of Dacia which had been abandoned during the previous century. Constantine built a new imperial residence in place of Byzantium, naming it New Rome. However, in Constantine's honour, people called it Constantinople, which would later be the capital of the Eastern Roman Empire for over one thousand years. Because of this, he is thought of as the founder of the Eastern Roman Empire.