From Wikipedia

Highland Clans

Clan Mackenzie

Clan Mackenzie is a Highland Scottish clan, traditionally associated with Kintail and lands in Ross-shire.
The Mackenzies were of Celtic stock and were not among the clans that originated from Norman ancestors. They are believed to be related to Clan Matheson and Clan Anrias, all three descending from the 12th century Gill'Eòin of the Aird. Based initially in Kintail, the clan was recorded at Eilean Donan on Loch Duich, a stronghold with which it was for many centuries associated. For generations, the constable of Eilean Donan was traditionally Macrae of Inverinate, with the result that the Clan Macrae became known as "Mackenzie's shirt of mail". There were also strongholds at Kilcoy Castle and Brahan Castle and the Mackenzies of Tarbat had their seat at Castle Leod, in Strathpeffer in the 17th century. 

There was a tradition - not borne out, however, by any tangible evidence or confirmation and quite possibly invented by the Earl of Cromartie - that the family deduced its descent from a member of the House of Geraldine, in Ireland (whence sprang the noble families of Leinster, Desmond, &c.), who, with a considerable number of his followers, was stated to have settled in Scotland about the year 1261 and to have so powerfully aided King Alexander III in repelling the invasion of Haco, King of Norway. He was reportedly rewarded by a grant of the lands of Kintail, in the County of Ross, which were erected into a free Barony by charter, dated 9 January 1266. Therefore, Colin Fitzgerald was the first feudal Baron of Kintail.