Major Events Mar 12 Witiges, King of the Ostrogoths, ends his siege of Rome, retreats to Ravenna, leaving the city in the hands of victorious Byzantine General Belisarius Born in 538 AD Gregory of ToursNovember 30 More People Born in 538 AD 537 AD History by Year 540 AD Medieval Popes Gregory I Gregory XIII Julius II Julius III Leo X Pius V