Julius I was the bishop of Rome who held office from 337 until his death in 352. A native of Rome, he was selected to succeed Pope Mark following a four-month vacancy in the papal seat. He is primarily remembered for his involvement in the Arian controversy, specifically for his defense of Athanasius of Alexandria. By supporting Athanasius against the decisions of Eastern bishops, Julius asserted the growing authority and primacy of the Roman see over other regions.