The Mackenzies were of Celtic stock and were not among the clans that originated from Norman ancestors. Descendants of the long defunct royal Cenél Loairn of Dál Riata, they are believed to be related to Clan Matheson and Clan Anrias. All three descend from the 12th century GillEòin 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 Mackenzies 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.