The name Mackinney, or MacCoinnich, as it appears in Gaelic, is generally taken to mean "son of Kenneth", and the original Kenneth, who lived in the thirteenth century, is said to have descended from a younger son of Gilleoin of the Aird. The Mackenzies were, without doubt, of Celtic stock and were not among the clans that originated from Norman ancestors. We know little about the generations immediately following Gilleoin, but in 1267 Kenneth was living at Eilean Donan, a stronghold at the mouth of Loch Duich. He must have been an important vassal, for the Earl of Ross appears to have married Kenneth's aunt and thus strengthened the relationship which already existed between the two families. At the start of the fifteenth century the Earldom of Ross came, through marriage, into the hands of the powerful family of MacDonald, who owned vast property on the west of Scotland and called themselves, at first without the King's authority, Lords of the Isles. In this way the Mackenzies became vassals, not of their kinsmen the Earls of Ross but of the MacDonalds. The Lords of the Isles were so powerful and claimed the allegiance of so many clans that they very soon came into conflict with the King. The earliest of their rebellions took place in 1428 after James I had imprisoned the Lord of the Isles and several chiefs who were attending a Parliament at Inverness.