 It was then that John MacSween approached Edward I of England, asserting that one of the king's enemies, Sir John Menteith, had deprived MacSween of his inheritance.Between 1301 and 1310, John MacSween was in the service of the English in the hope of keeping alive his family's claim against the Menteiths.During the Great Cause, which led to the First War of Scottish Independence, the MacSweens were supporters of the powerful MacDougall Lords of Lorne who supported John Balliol as patriots, as long as John was king of Scotland.