A church divided
In 632 the newly established Northumbrian church was in danger.
Edwin, King of Northumbria, was killed by an alliance between a Cadwalla of Gwynedd (a Christian king) and Penda of Mercia (a pagan king).Then, when Oswald reclaimed his throne as King of Northumbria, he turned to the Irish monastery of Iona, where he had spent time in exile, rather than to Rome.
Iona sent the Irishman Aidan to Northumbria to be its bishop. Aidanfounded his see at Lindisfarne in Northumberland, rather than at York. Aidan was a great hero of the early English church, as described by the Anglo-Saxon monk Bede.
Lindisfarne became a training centre for missionaries, who went on to convert Mercians, East Angles, East Saxons and South Saxons to Christianity.
Where Rome’s mission in England had failed, the Irish missionaries succeeded in a spectacular fashion, and they didn’t stop here! At the same time they were also founding churches along the western coast of Scotland and the Isles.
Converts in northern Britain tended to remain loyal to Iona and its traditions. But, by the middle of the seventh, these traditions came under question and challenge. For example, the rest of the church in England and Ireland adopted new Roman methods of calculating the date of Easter. This was never more obvious than in the early 660s, when the Northumbrian court saw King Oswiu and his followers celebrate Easter according to Ionan traditions, and his Kentish wife Eanflæd and their son Alhfrith, hold ceremonies in a different week.
Oswiu called the synod of Whitby to settle the issue. He decided in favour of St Peter of Rome over St Columba of Iona. At this point Irish influence on the English church waned, and continued to wane after new links with Rome were forged.
In 668, Pope Vitalian appointed Theodore as archbishop of Canterbury. Theodore came from Tarsus in Asia Minor, and he worked hard to unite the church in England, and to create new dioceses, and introduce new learning. He also helped to depose of people who opposed his works, including St Wilfred of York.