In 673 St Etheldreda founded a double monastery here for monks and nuns. It was destroyed by the Danes in 870, but restored, for monks only, in 970. The see of Ely was formed in 1109; the prior and monks became the cathedral chapter. At the Dissolution the prior became dean and eight canonries were founded (1541). The cathedral is famous for its central octagon (1322–8), with its domed roof (known as ‘The Lantern’, completed in the 1340s) and other 14th-cent. work, including the magnificent Lady Chapel.