Flavius Valerius Constantinus was emperor of Rome from 306 to his death in 337. He inherited the office of Caesar from his father Constantius, one of Diocletian’s Tetrarchy, and consolidated his reign through civil wars. He made Constantinople his capital in the east. Around 312, during a military confrontation with Maxentius, Constantine is reported to have had a dream or vision which catalysed his conversion to Christianity. Subsequently he put a stop to persecution of Christians and made Christianity (and all other religions) legal for the first time in the Roman Empire. He became a patron of the church and summoned the Council of Nicaea in 325, which produced the Nicene Creed and denounced the Arian heresy. Constantine was baptised on his deathbed in hopes that a late baptism would wash away his sins, and died on 22 May 337 in Nicomedia.