[1] Following the death of John Bullock, Bishop of Ross, in either 1439 or 1440, Munro was postulated as Bullock's successor by the cathedral chapter; his postulation, rather than election, occurred because Munro had a "defect of birth", being the son of an unmarried woman and a priest.

[2] Despite much effort and expense, the postulation was rejected by Pope Eugenius IV, who provided instead Thomas Tulloch, the cathedral Dean.

[2] In compensation, on 4 March 1441, Eugenius granted Munro a pension of £40, to be taken from the mensal revenues of the Bishop of Ross.

[2] Munro however sought confirmation of his postulation from the Anti-Pope, Felix V, at Basel in the Kingdom of Germany.

[2] Munro is heard of again as the Commissary of the diocese of Ross in 1451, while still holding the archdeaconry; he had died by 24 October 1454.