The ancient kingdom of East Anglia was converted to Christianity by a Burgundian monk, Felix, who became the first bishop of East Anglia—the diocese, as usual, being coextensive with the kingdom—and fixed his see at Dunwich in 630. The see was subdivided by the Archbishop Theodore, the great organiser of the English Church, in 669. It was again reunited, and the cathedral was at Elmham, till the bishop migrated in 1070 to Thetford, and in 1094 to Norwich. The present cathedral was commenced in 1096 by Herbert de Losinga, who is usually described as a Lorrainer. He is recorded to have finished the whole cathedral before his death in 1119 as far as the altar of the Holy Cross, which would stand in front of the choir-screen. His successor finished the nave and west front, and carried up the central tower (1121-1145). The plan is that of Gloucester and Leominster; the rudiments of it appear in the ancient church at Bethlehem and in St. Sepulchre at Jerusalem. There was an enormously long aisled nave of fourteen bays, aisleless transepts of three bays, an aisled presbytery of five bays, a semicircular apse, a processional aisle or ambulatory encircling the apse, and three segmental chapels radiating from the ambulatory; also eastern apses to the transepts. All this remains, except the easternmost apsidal chapel, which was replaced in the thirteenth century by an oblong Lady chapel, itself pulled down in the sixteenth century; and the apse of the south transept, which was replaced by an oblong chapel in the thirteenth century.