Only two Popes, Leo I and Gregory I, have been given the popular title of the Great. Both served in the difficult times of the barbarian invasions of Italy. Gregory also knew the horrors of plague, pestilence, and famine. He was born of a patrician family about 540, and became Prefect of Rome in 573. Shortly thereafter he retired to a monastic life in a community which he founded in his ancestral home on the Coelian Hill. Pope Pelagius II made him Ambassador to Constantinople in 579, where he learned much about the larger affairs of the Church. Not long after his return home, Pope Pelagius died of the plague, and in 590 Gregory was elected as his successor.