 As a subdean of the diocese of Glasgow he had a close relationship with Bishop William Turnbull.By 1450, de Durisdeer was a dean of the diocese of Aberdeen, and in the period 1451–1453 he effectively became the ambassador of King James II of Scotland to the papal court.De Durisdeer was highly thought of by Pope Nicholas V. On 7 May 1455, Pope Calixtus III personally provided Andrew to the bishopric of Glasgow, despite not yet having risen to the rank of sub-deacon.