Alexander II (August 24, 1198 - July 6, 1249), king of Scotland, son of William I, the Lion, and of Ermengarde of Beaumont , was born at Haddington in 1198, and succeeded to the kingdom on the death of his father on 4 December 1214.

The year after his accession the clans MacWilliam and MacHeth, inveterate enemies of the Scottish crown, broke into revolt; but loyalist forces speedily quelled the insurrection. In the same year Alexander joined the English barons in their struggle against John, and led an army into England in support of their cause; but after John's death, on the conclusion of peace between his youthful son Henry III and the French prince Louis, the Scottish king joined in the pacification. Diplomacy further strengthened the reconciliation by the marriage of Alexander to Henry's sister Joanna (or Joan) on June 18 or June 25, 1221.

The next year marked the subjection of the hitherto semi-independent district of Argyll. Royal forces crushed a revolt in Galloway in 1235 without difficulty; nor did an invasion attempted soon afterwards by its exiled leaders meet with success. Soon afterwards a claim for homage from Henry of England drew forth from Alexander a counter-claim to the northern English counties. The two kingdoms, however, settled this dispute by a compromise in 1237.

Joanna died in March, 1238 in Essex, and in the following year, 1239, Alexander remarried. His second wife was Mary of Coucy (Marie de Coucy). The marriage took place on May 15 1239, and produced one son, the future Alexander III, born in 1241.

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 next year at Newcastle. Alexander now turned his attention to securing the Western Isles, which still owed a nominal allegiance to Norway. He successively attempted negotiations and purchase, but without success. Alexander next attempted to dissuade Ewen, the son of Duncan, Lord of Argyll, to sever his allegiance to the Norwegian king. Ewen rejected these attempts, and Alexander sailed forth to compel him.

But on the way he suffered a fever at the Isle of Kerrera in the Inner Hebrides, and died there in 1249. He was buried at Melrose Abbey, Roxburghshire. His son Alexander III succeeded him as King of Scots.