He was born around 1386 (or soon before), which is known because he was a
Master of Arts in 1406, a requirement of which was being at least 20 years old. The name "de Crannach" comes from the former
sheriffdom of Banff, either
Crannach in Grange parish or
Cranna in Marnoch parish. Three of his brothers are known; one, William, was a prominent
Augustinian canon who became
abbot of Inchaffray (1430–1433 or 1435), while another, David de Crannach, was sub-dean of Dunkeld and
dean of Brechin. His third brother, Robert de Crannach, was
precentor of Brechin from 1440 to sometime between 1453 and 1457, as well as dean of Dunblane (1430–1439 or 1440). His uncle, Adam de Crannach (also "de Aberdeen"), was also a prominent Augustistian, serving as
abbot of Scone between 1418 and 1432. A student of the
University of Paris in the early 15th century, he was
Bachelor of Arts in February 1405, and a
Licentiate and Master of Arts in May 1406. He was regent of the Arts between 1406 and his departure from the university in 1417. ==Diplomat and churchman==