Construction work continued for much of the 13th century, including the central tower and spire, a bell-tower at the north-west corner of the nave (a south-west tower was added in the 14th century). Edward I of England visited the cathedral in August 1301 during the First War of Scottish Independence, making offerings over four days at the high altar and the tomb of Saint Mungo. Following the killing of John Comyn at Greyfriars, Dumfries in February 1306, Robert the Bruce hurried to Glasgow where he met with Robert Wishart, the "warrior" Bishop of Glasgow, in whose diocese the murder had been committed.