Reigned from 337 to 352. Confessor, born and died Rome. His pontificate is celebrated for his judicious and firm intervention in the Arian controversies. He convened a synod at Rome for the purpose of judging Athanasius and, in spite of the refusal of the Arian bishops to attend, he acquitted and reestablished Athanasius and Marcellus of Ancyra. The catalog of the feast-days of saints probably came into use during his pontificate. He erected two basilicas in Rome and three churches outside the walls of Rome. Feast, April 12,.