Answer
Constantine was born in Naissus, Dacia Mediterranea, in the Roman Empire, which is present-day Niš, Serbia. He was born on February 27, 272 AD. His mother was Helena, a Bithynian Greek, and his father was Constantius Chlorus, a Roman army officer. Constantine became the sole ruler of the Roman Empire in 324 AD after defeating his rivals in a series of civil wars.