Constantine the Great (;
Greek: Κωνσταντῖνος ὁ Μέγας; 27 February 272 AD – 22 May 337 AD), also known as
Constantine I or
Saint Constantine (in the
Orthodox Church as
Saint Constantine the Great, Equal-to-the-Apostles), was a
Roman Emperor from 306 to 337 AD. Constantine was the son of
Flavius Valerius Constantius, a Roman army officer, and his consort
Helena. His father became
Caesar, the deputy emperor in the west in 293 AD. Constantine was sent east, where he rose through the ranks to become a military tribune under the emperors
Diocletian and
Galerius. In 305, Constantius was raised to the rank of
Augustus, senior western emperor, and Constantine was recalled west to campaign under his father in
Britannia (Britain). Acclaimed as emperor by the army at
Eboracum (Modern-day
York) after his father's death in 306 AD, Constantine emerged victorious in a series of civil wars against the emperors
Maxentius and
Licinius to become sole ruler of both west and east by 324 AD.