Islay today is on the edge of Scotland, but 1,500 years ago it was the centre of the Argyll/Ulster kingdom of Dál Riata and was a major staging post for Irish Christian missionaries. The Lordship of the Isles was a Celtic kingdom, controlled from Finlaggan by the MacDonalds of Islay–themselves descended from Dòmhnall, grandson of Somerled. Its core was the Hebrides, mainland Argyll and the Glens of Antrim, but at its height MacDonald territory stretched up the Great Glen to Ross-shire, beyond to Buchan and the Mearns, and south to Greenan in Ayrshire. The Lords’ main residence was on Eilean Mòr (the Large Island), the ruins of which can be seen along with its chapel and fourteenth-century grave slabs. Adjacent to Eilean Mòr is an Iron Age crannog, Eileen na Comhairle (the Council Island), where the Parliament of the Isles met to adjudicate on matters of law. The Lordship commanded great loyalty which continued after its forfeiture by James IV in 1493.