Ely has been a place of Christian worship since at least 673, when Etheldreda, daughter of the king of East Anglia, founded a nunnery there. She later became a saint.
'... Ely became a cathedral, as part of the Norman reforms of the English church.'
Ely was sacked by the Danes in the 870s, but it was rebuilt in anglo-Saxon times, and by the 10th century had become a monastery for men. Nothing survives of the Anglo-Saxon church, which was entirely demolished when the present structure was built after the Norman Conquest. In 1109 Ely became a cathedral, as part of the Norman reforms of the English church.