[livius]

the mother church of worldwide Anglicanism which was founded in 597 by St Augustine,

Gimme a break! The Anglicans must have been taking history-writing lessons from the Soviets. Talk about an invented past.

[Mike Fieschko]

The entire sentence makes it clear that the writer means that the cathedral, not Anglicanism, was founded in A.D. 597:

The cathedral, the mother church of worldwide Anglicanism which was founded in 597 by St Augustine, was the scene of the murder of Thomas Becket in 1170 and has survived extensive bombing of the city during the Second World War.

Anglicanism could not have been the scene of St Thomas Beckett's murder, nor could Anglicanism have been what 'survived extensive bombing of the city during the Second World War'.