Justinian I

Justinian I ruled the Eastern Roman (Byzantine) Empire from Constantinople from 527 to 565. Born to a peasant family in the Balkans, he rose through the patronage of his uncle, the emperor Justin I. With his wife Theodora he reorganized the government, sponsored a great codification of Roman law, the Code of Justinian, that later shaped European legal systems, and built the Hagia Sophia. His generals, above all Belisarius, reconquered North Africa and Italy.

His reign was also struck by disaster. In 536 writers across the Mediterranean, including his historian Procopius, recorded that the sun had lost its strength for a year. In 541 to 542 bubonic plague reached the empire, the first known pandemic of the disease, now called the Plague of Justinian. Historians debate how far the cold and the plague weakened the empire, but both drained its population and treasury, and his ambitions proved hard to sustain.