Gamelin's career began during the reign of
Alexander II, when he became a
Papal chaplain by 1245. He held the church of
Kilbucho in Peeblesshire and was connected to important political families like the Comyns and Fitz Gilberts, who played major roles in Scottish politics. By April 1245, he had become a canon of
Glasgow, and by the early 1250s, he succeeded Robert, Abbot of Dunfermline, as Chancellor of Scotland. Gamelin, Bishop of St Andrews, had a brother named Master John, who is recorded as a witness to one of the bishop’s official acts. It is possible that this Master John was the same individual as
John de Glasgu, Gamelin’s chaplain and potentially the earliest documented bearer of the
Glasgow surname. == Bishop of St Andrews and political struggles ==