When we, Constantine and Licinius, emperors, had an interview at Milan, and conferred together with respect to the good and security of the commonweal, it seemed to us that, amongst those things that are profitable to mankind in general, the reverence paid to the Divinity merited our first and chief attention, and that it was proper that the Christians and all others should have liberty to follow that mode of religion which to each of them appeared best; so that that God, who is seated in heaven, might be benign and propitious to us, and to every one under our government. ~ Constatine the Great - (Edict of Milan proclaiming proclaimed religious toleration in the Roman Empire, issued by Constantine and Licinius)
His coins give his name as M., or more frequently as C., Flavius Valerius Constantinus. He was born at Naissus, now Nisch in Servia Nis, Serbia --Ed., the son of a Roman officer, Constantius, who later became Roman Emperor, and St. Helena, a woman of humble extraction but remarkable character and unusual ability. The date of his birth is not certain, being given as early as 274 and as late as 288. After his father's elevation to the dignity of Caesar we find him at the court of Diocletian and later (305) fighting under Galerius on the Danube. When, on the resignation of his father, Constantius was made Augustus, the new Emperor of the West asked Galerius, the Eastern Emperor, to let Constantine, whom he had not seen for a long time, return to his father's court. This was reluctantly granted. Constantine joined his father, under whom he had just time to distinguish himself in Britain before death carried off Constantius (25 July, 306). Constantine was immediately proclaimed Caesar by his troops, and his title was acknowledged by Galerius somewhat hesitatingly. This event was the first break in Diocletian's scheme of a four-headed empire (tetrarchy) and was soon followed by the proclamation in Rome of Maxentius, the son of Maximian, a tyrant and profligate, as Caesar, October, 306.