Constantine the Great

Flavius Valerius Constantinus was born around 272 CE at Naissus — modern Niš in Serbia — the illegitimate son of Constantius Chlorus, a senior officer who would eventually become Caesar of the west. His mother Helena was of obscure provincial origin, possibly a stable-girl or innkeeper; she would later become a saint. When Diocletian's Tetrarchic system split the empire into four co-rulers in 293 CE, Constantius was elevated as Caesar under Maximian in the west, but his son Constantine remained in the east, effectively a hostage at Diocletian's court in Nicomedia. It was an education: Constantine watched Diocletian administer the empire, suppress the Great Persecution of Christians (303–312 CE), and abdicate in 305 CE. When Constantius died at York in July 306 CE, his troops immediately proclaimed Constantine Augustus — a direct violation of the Tetrarchic succession principle. Over the next eighteen years Constantine destroyed his rivals one by one with a strategic patience that bordered on the calculating. The pivotal moment came on 28 October 312 CE at the Milvian Bridge, north of Rome, where Constantine faced the western usurper Maxentius. The night before, according to both Christian and pagan sources, Constantine experienced a vision — either a cross of light over the sun inscribed 'by this sign, conquer' (Eusebius's account) or a dream ordering him to mark his soldiers' shields with the Chi-Rho monogram (Lactantius's account). He did both. Maxentius's forces were driven into the Tiber; Maxentius drowned. Constantine entered Rome as the undisputed master of the west. He did not credit Jupiter or Mars. In June 313 CE, Constantine and the eastern emperor Licinius issued what is called the Edict of Milan — more accurately a letter to provincial governors — guaranteeing freedom of religion to all citizens, specifically including Christians, and ordering that confiscated church property be returned. It did not make Christianity the state religion, but it ended a decade of brutal persecution and funded the rapid expansion of the church. The Arch of Constantine in Rome (315 CE), the best-preserved triumphal arch in the city, commemorated the Milvian Bridge victory; its inscriptions attribute the victory to 'divine inspiration' — deliberately vague, but everyone understood. In 324 CE Constantine defeated and executed Licinius, becoming sole emperor of a reunited empire for the first time since Diocletian. His response to sole power was radical. In 325 CE he summoned approximately 300 bishops to Nicaea — the first ecumenical council in Christian history — to settle the Arian controversy over whether Jesus was of the same substance as God the Father. Constantine presided in person, in imperial gold robes, and guided the council toward the formulation that became the Nicene Creed, still recited by billions today. His second great act of sole rule was the founding of Constantinople. On 11 May 330 CE, he dedicated Byzantium — renamed Constantinopolis — on the Bosphorus as the new eastern . The city had matchless natural defences, controlled the straits between Europe and Asia, and was on no pagan sacred ground. He built it at stunning speed: a new forum, a hippodrome beside the Hagia Eirene (the city's first great church), a palace, an aqueduct, and walls. He stripped marble and statuary from across the empire to decorate it. The city he built would be the of the eastern Roman Empire for 1,123 years, until 1453. Constantine's personal Christianity was genuine but strategically managed; he was not baptised until he lay dying, in 337 CE, following the common late-antique practice of deferring baptism to cleanse a lifetime's sins. He died at Ancyrona near Nicomedia on 22 May 337 CE. He was buried in the Church of the Holy Apostles in Constantinople, in a sarcophagus placed at the centre of twelve symbolic apostle-tombs — positioning himself, unmistakably, as the thirteenth apostle.

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