Before becoming bishop, William was rector of Eddleston, a prebendary of Glasgow, and archdeacon of Lothian.
)[1] On 11 September 1233, he was consecrated at Glasgow Cathedral by Andreas de Moravia, Bishop of Moray.
In 1240, William and David de Bernham, Bishop of St Andrews, were summoned to Rome by Pope Gregory IX, in order to attend a general council.
Bishop William's episcopate saw continued work on the cathedral and significant expansion in the resources of the diocese.
William had a residence near the village of Ancrum in the Scottish borders although its precise location has been investigated for some years.