Cyprian, bishop of Carthage, is one of many Christians martyred for refusing to sacrifice to the Roman gods

St Anthony, one of the early Christian hermits in the Egyptian desert, is tempted by terrifying hallucinations

The emperor Diocletian initiates a sustained persecution of Christians in the Roman empire

Constantine, preparing for battle against a rival at the Milvian Bridge, orders his men to wear a Christian symbol, the Chi-Rho, on their shields

Constantine meets his co-emperor Licinius in Milan, and persuades him to follow a policy of encouraging the Christians

Warming to his new Christian role, Constantine summons more than 300 bishops to Arles to discuss the controversial issue of Donatus

Constantine founds several churches in Rome, among them the first St Peter's

Pachomius organizes in Egypt the first community of Christian monks, at Dandara on the Nile

Constantine convenes a council of 200 bishops at Nicaea to discuss the beliefs of Arius, which are deemed to be heresy

Helena, mother of the emperor Constantine, discovers in Jerusalem the cross on which Christ died - or so it is later claimed

Constantine's new Christian city on the site of Byzantium is inaugurated, as Constantinople

Constantine is at last baptized a Christian in Nicomedia, just a few days before his death

Frumentius, brought to Ethiopia as a slave, becomes the kingdom's first Christian bishop

Greece begins to find a new and influential role in a Christian context, through the Byzantine empire

St Martin founds the first monastery in western Europe, at Ligugé near Poitiers

An apocryphal story states that Julian the Apostate, dying at Tarsus, acknowledges the victory of the Galilean, Jesus Christ

A document is distributed by the bishop of Alexandria, formally establishing the contents of the New Testament

The Codex Sinaiticus, the earliest surviving manuscript of the complete New Testament, is copied out - probably in Egypt

St Jerome settles in Bethlehem, where his holy women organize a monastery for his residence and a nearby convent for themselves

St Ambrose asserts the authority of the church, refusing communion to the emperor Theodosius in Milan until he does penance for a massacre

St Augustine reveals that as a young man, studying and teaching in Carthage, he often prayed for 'chastity and continence, but not yet'

St Jerome, in Bethlehem, completes the Latin translation of the Bible which later becomes known as the Vulgate

Prompted by the fall of Rome to the Visigoths, St Augustine undertakes a great work of Christian philosophy, the City of God

A council is convened at Ephesus to consider the theology of Nestorius, which is judged to be heretical

St Patrick creates a strong tradition of Celtic Christianity in Ireland, from his base in Armagh