Zachary was a Calabrian Greek — the last pope born in the empire's Greek-speaking lands until John Paul II. He succeeded Gregory III in 741 and reigned eleven years. He maintained close personal relations with Boniface; their surviving correspondence is the principal source for the organization of the German Church.
His most consequential decision came in 751, when the Frankish mayor of the palace Pippin the Short sent envoys to Rome to ask whether it was 'just' that those who held the power should not also bear the title of king. Zachary answered yes — making possible the legal deposition of the last Merovingian Childeric III and the elevation of Pippin as the first Carolingian king, anointed by St. Boniface at Soissons that November. From this papal verdict descends the entire medieval theory of Christian kingship.
He translated the Dialogues of St. Gregory the Great into Greek, the only Latin patristic text translated in this direction in the entire early medieval period. He restored multiple Roman basilicas and made decisive reforms in clerical discipline. He died in Rome on March 22, 752.