Peterborough and Ely were the two great monasteries on the Fens. The Saxon monastery built before the Norman conquest, c 655, was sacked by the Danes in 870. A second Saxon church, built in the 10C as a Benedictine abbey, was burnt down in 1116. The current cathedral was rebuilt between 1118 and 1238. Behind the main, Early English Gothic-style façade, the superb interior is an example of Norman architecture.