Monks in Ireland live in stone beehive cells on rocky islands, to achieve maximum discomfort

Small ivory panels, with Gospel scenes carved in relief, provide a delicate beginning to the story of Christian sculpture

Clovis and some 3000 of his soldiers are baptized in a massive ceremony at Reims

Dionysius Exiguus, commissioned by the pope to improve chronology, makes an error of at least four years in his selected event for AD 1

St Benedict gathers fellow hermits at Subiaco into a series of small monasteries

The monastery of St Catherine's in Sinai is founded by Justinian, and will accumulate one of the world's greatest collections of icons

St Finnian founds the first of Ireland's great Celtic monasteries, at Clonard

St Benedict founds a monastery at Monte Cassino and writes a Rule for the monks which becomes the basis of the Benedictine order

Christianity reaches the kingdom of Dongola, in present-day Sudan

St Columba establishes a monastery on the island of Iona, from which Celtic Christianity is carried to Scotland and northern England

St David founds monasteries in Wales and makes his base at Mynyw, a place now known after him as St David's

The word filioque ('and from the Son') becomes a major bone of contention between the Roman Catholic and Eastern Orthodox churches

Augustine, arriving with a party of monks from Rome, reaches Canterbury and is well received by the pagan king of Kent

Ritual intoning of the psalms, derived from Jewish synagogues, is formalized in Christian worship as Gregorian chant

St Columban founds a monastery at Bobbio, the furthest outpost of Celtic Christianity

When the Persians sack Jerusalem, they carry off to Ctesiphon Christianity's most sacred relic - the True Cross

The Irish monk St Aidan moves from Iona to establish a monastery on Lindisfarne

The Byzantine emperor Heraclius recovers the True Cross from Ctesiphon

The Coptic Christians of Egypt become isolated after the Muslim conquest

The Book of Durrow, one of the earliest of the great Celtic manuscripts, is written and illuminated in Ireland

Jews and Christians, sharing with Muslims the status of 'people of the book', are promised religious tolerance in the Qur'an

The king of Northumbria summons a synod at Whitby to hear the arguments of Roman and Celtic Christians, then opts for Rome

Willibrord, recently arrived from England to convert the Frisians, is consecrated archbishop of a new see in Utrecht

The Lindisfarne Gospels are written and illuminated by Celtic monks on the Scottish island of Lindisfarne

The emperor Leo III launches the iconoclastic controversy, sending soldiers to smash the great image of Christ over the gateway to his palace