He was the second son of Hector Og Maclean, 15th Clan Chief. His mother was the daughter of Colin Mackenzie of Kintail. He became Clan Chief at the death of his brother in 1626. He was originally contacted by Archibald Campbell, 1st Marquess of Argyll at the beginning of the Wars of the Three Kingdoms (1644–1651), but he sided with the Royalists.