Lincoln Cathedral, dedicated to St Mary, is a magnificent Gothic building which, with the castle, dominates the city. It dates from the 11th century and is the third largest cathedral in Britain (after St Pauls and York Minster). From 1311 to 1549, when its central spire collapsed, Lincoln Cathedral was the tallest building in the world. Highlights include many ornate carvings, two enormous rose windows, the treasury and medieval libraries. Notable burials/tombs include Katherine Swynford, mistress then wife of John of Gaunt, the cadaver tomb of Bishop Richard Fleming and the entrails of Eleanor of Castile, first wife of Edward I. The Cathedral also owns one of four surviving copies of Magna Carta from 1215.