MacDonald was the second son of John of Islay, Lord of the Isles and Princess Margaret Stewart of Scotland, daughter of King Robert II.
Not being satisfied with his inheritance, he led a revolt against his brother Donald of Islay, Lord of the Isles as MacDonald was recognized as the heir-apparent (tanistry).
The rebellion started in 1387 and went on into the 1390s, and MacDonald obtained the support of the powerful Clan MacLean kindred.
Though he may have used this title, the MacEoin Bissets continued to hold the Glens of Antrim until as late as 1522, when the last known died in battle.
[2] MacDonald successfully led the reserve at the Battle of Harlaw just north of Inverurie in Aberdeenshire on 24 July 1411,[3] and later fought against Robert Stewart, Regent Albany who had forayed into Argyll to try and defeat Donald of Islay.