From 1336 onwards John began to style himself "Dominus Insularum"—"Lord of the Isles", a title that implied a connection to the earlier Kings of the Isles and by extension a degree of independence from the Scottish crown; this honorific was claimed by his heirs for several generations. The MacDonalds had thus achieved command of a strong semi-independent maritime kingdom, and considered themselves equals of the kings of Scotland, Norway, and England. Initially, their power base was on the shores of Loch Finlaggan in northeastern Islay, near the present-day village of Caol Ila. Successive chiefs of Clan Donald were proclaimed Lord of the Isles there, upon an ancient seven-foot-square coronation stone bearing footprint impressions in which the new ruler stood barefoot and was anointed by the Bishop of Argyll and seven priests. The Lord's advisory ""Council of the Isles"" met on Eilean na Comhairle ("Council Island"), in Loch Finlaggan on Islay, within a timber framed crannog that had originally been constructed in the 1st century BC. The Islay Charter, a record of lands granted to an Islay resident in 1408, Brian Vicar MacKay, by Domhnall of Islay, Lord of the Isles, is one of the earliest records of Gaelic in public use, and is a significant historical document. In 1437, the Lordship was substantially expanded when Alexander, the Lord of the Isles, inherited the rule of Ross maternally; this included Skye. The expansion of MacDonald control caused the ""heart of the Lordship"" to move to the twin castles of Aros and Ardtornish, in the Sound of Mull. In 1462, the last and most ambitious of the Lords, John MacDonald II, struck an alliance with Edward IV of England under terms of the Treaty of Ardtornish-Westminster with the goal of conquering Scotland. The onset of the Wars of the Roses prevented the treaty from being discovered by Scottish agents, and Edward from fulfilling his obligations as an ally. A decade later, in 1475, it had come to the attention of the Scottish court, but calls for forfeiture of the Lordship were calmed when John quitclaimed his mainland territories, and Skye. However, ambition wasn't given up so easily, and John's nephew launched a severe raid on Ross, but it ultimately failed. Within 2 years of the raid, in 1493, MacDonald was compelled to forfeit his estates and titles to James IV of Scotland; by this forfeiture, the lands became part of Scotland, rather than a crown dependency.