Constantine I

Constantine the Great made Christianity legal, founded a new capital, and reunited an empire that had been governed by four men. Born at Naissus around AD 272, the son of the officer Constantius Chlorus and a woman of humble origins, Helena, he was raised at Diocletian's court in the east, effectively as a hostage guaranteeing his father's conduct. He joined his father in Britain, and when Constantius died at York in 306 the troops proclaimed Constantine — which the Tetrarchy's succession rules did not permit and which began eighteen years of civil war. He defeated Maxentius at the Milvian Bridge in October 312. His biographers report that he saw a sign in the sky and had his men mark their shields with the chi-rho; whatever happened, he attributed the victory to the Christian God and never went back on it. The Edict of Milan in 313 with Licinius ended persecution and restored confiscated church property. He funded basilicas, exempted clergy from taxation, gave bishops civil jurisdiction, and made Sunday a rest day. He summoned the Council of Nicaea in 325 to settle the Arian dispute, presided over it, and imposed a creed on a church that had never had one — the state now had a stake in doctrine. He defeated Licinius in 324 and founded Constantinople on the site of Byzantium, dedicating it in 330; it lasted eleven centuries. He had his eldest son and his wife killed in 326 for reasons never explained. He was baptised on his deathbed in 337.

• Lived: 272 CE – 337 CE
• Nationality: Roman
• Roles: ruler, religious_leader