Flavius Valerius Constantinus, better known as Constantine the Great, was born on February 27, 273 or 274. His father was Constantius Chlorus, afterwards Caesar and Augustus, but at the time of Constantine's birth merely a promising officer in the Roman Army. Constantius belonged to one of the leading families of Moesia and his mother was a niece of the capable and soldierly Claudius, the conqueror of the Goths. Helena is said to have been the daughter of an innkeeper of Drepanum, and Constantine's enemies lost no opportunity of dwelling upon the obscurity of his ancestry upon mother's side. But that he was born in wedlock is beyond question. Helena, who later became St. Helena, is still remembered as the Christian Empress. There is, however, nothing to support the assertion sometimes made, that she was already baptized before Constantine's birth and her early influence ultimately brought him to Christianity. Such facts about her life as are known would suggest the contrary - Eusebius of Caecarea declares that Constantine in fact converted his mother. There are, however, other indications that Helena was not a Christian during her son's early years. At what date Helena did embrace Christianity remains a mystery. Nor can anyone say with certainly what gods she worshipped during her son's childhood.
The uncertainty attaching to the year of Constantine's birth attaches even more to its place. Where he was born is almost not known. The name of the places have been proposed: Colchester in Britain, Drepanum, a city on the shores of the Gulf of Nicomedia on the southern coast of the Bosphorus, and the town of Naissus, now Nish, in the province of Dacia in the Balkans. None of them can certainly be excluded, but Colchester is the least likely of the three. No one now believes that he was born in Britain - a pleasing fiction which was invented by English monks, who delighted to represent his mother Helena as the daughter of a British King, though they were quite at a loss where to locate his kingdom. The only foundation for this was a passage in one of the Panegyrists, who said that Constantine had bestowed luster upon Britain. There is no evidence that Constantius visited Britain before he became Praetorian Prefect to Maximian in 286 or 287. The evidence for Constantine's birth at Drepanum in northern Asia Minor is not much convincing. It stands mainly on the facts that he renamed the city Helenopolis and its province Helenopontus in his mother's honor, and that the emperor Justinian beautified the city because his illustrious predecessor had been born there. Justinian's act of piety was, however, performed two hundred years after Constantine's death and can scarcely be taken to prove anything. The weight of the evidence favors Naissus as Constantine's native town. His contemporary, Julius Firmicius, affirms it absolutely, and it is confirmed by the unnamed author quoted by Ammianus late in the fourth century. Naissus was an important city, and it would not be really remarkable that both Claudius should valiantly defend it and Constantius Chlorus' son be born there. It would held to fix the date and place Constantine's birth if there were hard evidence pointing to where Helena's father kept his inn, when Constantius began his service in the south Danubian area, and how long after the start of Helena's association with him her son was born. It is tempting to speculate that the inn was at or near Naissus, that Constantius met Helena while serving in the Gothic campaign, and that Constantine was born within a few miles of the side of his alleged imperial relation's greatest victory.
Of Constantine's early years we know almost nothing, though we may suppose that they were spent in the eastern half of the Empire. In 293 Constantine was betrothed to Fausta the daughter of Maximian, and in this year his father Constantius was made Caesar, and partially master of Gaul with the task assigned him of recovering Britain. Constantine had no learned education and served both the Augustus Diocletian and the Caesar Galerius as a tribune of the bodyguard. Under Galerius, Constantine fought against the Persians (297-298). But Constantine decided to depart from the east and rejoin his father Constantius in the west. It may well be true that Constantius