Alexander was born at Haddington, East Lothian, the only son of the Scottish king William the Lion and Ermengarde de Beaumont.

[3] In 1215, the year after his accession, the clans Meic Uilleim and MacHeths, inveterate enemies of the Scottish crown, broke into revolt, but loyalist forces speedily quelled the insurrection.

After the jarl swore oaths to his own innocence, Alexander took the opportunity to assert his claims to the mainland part of the Orkney jarldom.

During the same period, Alexander subjugated the hitherto semi-independent district of Argyll (much smaller than the modern area by that name, it only comprised Craignish, Ardscotnish, Glassary, Glenary and Cowal; Lorn was a separate province, while Kintyre and Knapdale were part of Suðreyar).

Royal forces crushed a revolt in Galloway in 1235 without difficulty;[5] nor did an invasion attempted soon afterwards by its exiled leaders meet with success.

[4] This was the Treaty of York, which defined the boundary between the two kingdoms as running between the Solway Firth (in the west) and the mouth of the River Tweed (in the east).

A threat of invasion by Henry in 1243 for a time interrupted the friendly relations between the two countries; but the prompt action of Alexander in anticipating his attack, and the disinclination of the English barons for war, compelled him to make peace the next year at Newcastle.

[9]Alexander attempted to persuade Ewen, the son of Duncan, Lord of Argyll (and King of the Isles), to sever his allegiance to Haakon IV of Norway.

The Hákonar saga Hákonarsonar records additional information, in that before attempting to invade the Isles, where Ewen held power, he was supposedly warned in a dream by St. Columba, St. Olaf and St. Magnus to desist.

The episode might be emblematic of a broader desire on the part of Alexander to bring the Kingdom of the Isles fully into the power of the Scottish Crown.