Pope John I was the bishop of Rome from 13 August 523 to his death. He was a native of Siena, in Italy. He was sent on a diplomatic mission to Constantinople by the Ostrogoth King Theoderic to negotiate better treatment for Arians. Although John was relatively successful, upon his return to Ravenna, Theoderic had him imprisoned for allegedly conspiring with Constantinople. The frail pope died of neglect and ill-treatment.

Justin I, also called Justin the Thracian, was Eastern Roman emperor from 518 to 527. Born to a peasant family, he rose through the ranks of the army to become commander of the imperial guard and when Emperor Anastasius died, he out-maneouvered his rivals and was elected as his successor, in spite of being around 68 years old. His reign is significant for the founding of the Justinian dynasty that included his eminent nephew, Justinian I, and three succeeding emperors. His consort was Empress Euphemia.