Pope Gregory I

Born around 540 to a senatorial family, Gregory served as prefect of Rome at thirty before retreating to a monastery he'd founded on his own estate. He re-entered public life as a papal ambassador, then became the 64th Bishop of Rome on 3 September 590. His administration outpaced emperors Maurice and Theodosius in feeding and governing the people of Rome as imperial power frayed. He dispatched missionaries to England - Augustine of Canterbury, Paulinus of York - and realigned the barbarian kingdoms: Franks, Lombards, Visigoths all turned from Arian Christianity to Roman allegiance, a shift that defined medieval Europe's religious map. He also fought the Donatist heresy in North Africa and reclaimed papal authority across Spain and France. His writings dwarfed those of any predecessor; the East called him "the Dialogist" for his Dialogues, and he overhauled Roman liturgy so thoroughly that the Middle Ages knew him as "the Father of Christian Worship." Canonized by popular acclaim immediately after his death on 12 March 604, he stands with Augustine, Jerome, and Ambrose as one of the four Great Latin Church Fathers - one of only three popes ever titled "the Great