In July 1300, Malcolm was granted safe conduct by the English so he could assail Scottish forces, on Scotland's western seaboard, with his galley fleet.
The invasion force was quickly overwhelmed by local forces, led by Dungal MacDouall, who was a supporter of the Balliols, Comyns and King Edward I of England with only two galleys escaping.
Malcolm was captured and summarily executed with the Irish sub king.
Alexander, Thomas and Reginald de Crawford were sent as prisoners to Carlisle, England, where they were executed.
The heads of MacQuillan and two Irish chiefs were sent to King Edward I.