Angus was a son of Donald Macaulay of  Luachair. Angus lived at Bosta; he married Catherine  Macdonald and was a parent of Ann, Mary and Zachariah.

His patronymic was Aonghas mac Dhomhnaill na Luachraich mhic Dhomhnaill mhic Dhughaill mhic Aonghais mhic Dhomhnaill, which would, unless by remarkable coincidence, make him a direct descendant of Domhnall Cam

An article in the Stornoway Gazette (Families of Lewis: Macaulay), written by William Matheson in the late 1950s, seems to have merged two families. According to local tradition he has conflated this Angus with Angus Macaulay of Croir.