On Colin's death, some time before 19 January 1414, Duncan became head of the Campbells of Loch Awe.
The documentary record calls him Campbell of Argyll, and gives his share of the liability for the king's ransom as 1500 merks, more than any other hostage save one.
During the minority of King James II, Duncan professed support and loyalty to the regency, while constantly expanding his power in Argyll, often at the expense of the Crown.
His other sons by his second marriage, Archibald, Duncan, and Neil, created the Campbell septs of Otter, Auchinbreck, and Ormidale, respectively.
[8] His grandson Colin, son of Archibald 'Gillespic,' (d. 1440) his only child by his first wife, succeeded him as Chief of the Clan Campbell.