Constantine I

(c. 285-337). Roman emperor from 306 to 337. On the night before battle with an imperial rival at the Milvian Bridge near Rome in 312, Constantine had a vision that apparently led to his conversion to Christianity. He saw a fiery cross in the heavens above the statement written in Greek, “In this sign you will conquer.” According to Lactantius (c. 250-c. 325), Constantine had a dream telling him to place on the shields of his soldiers a monogram of the Greek letters Chi (X) and Rho (P), which begin the word “Christ.” Under Constantine the labarum or military standard of the imperial Roman legions featured the Chi-Rho monogram. Slightly different accounts of this story are provided by Lactantius and Eusebius of Caesarea (c. 260-c. 339). After Constantine's victory at the Milvian Bridge, he and Licinius, emperor of the eastern empire, published the Edict of Milan in 313. It granted religious freedom throughout the Roman Empire. Constantine was a strong supporter of Christianity and sought to build a Christian empire. The concept of a Christian state can be traced to Constantine. He defeated Licinius in 324 and rebuilt Byzantium as his new capital. He renamed the city Constantinople. He convened and presided over the First Council of Nicaea (325). Constantine was baptized shortly before his death. He is celebrated as a saint in the eastern church. He was buried in the Church of the Twelve Apostles at Constantinople.