In the mid-11th century Robert, bishop of Coutances, started the building of this cathedral on the site of an earlier one which was distroyed in the 9th century. After Robert's death the work was carried on by his successor as bishop, Geoffrey de Montbray, appointed in 1048.
Geoffrey was on good terms with William, Duke of Normandy (known as the William the Conqueror), who attended the consecration of the new cathedral in 1056. The bishop subsequently accompanied William on the conquest of England, from the enormous profits of which the cathedral benefited greatly.
The cathedral suffered later from a serious fire, and in 1210 Bishop Hugues de Morville started to build the present Gothic cathedral, retaining however the dimensions and much of the fabric of the Romanesque building, substantial remains of which still underlie many of the walls and towers of the present cathedral.
The new cathedral was completed in 1274 and has remained basically unaltered since. The twin towers rise to almost 80m and its octagonal lantern tower stands over 57m high.