James Stewart, 1st Earl of Buchan (1442-1499) was a Scottish noble. He was the uncle of James III of Scotland who granted him the Earldom of Buchan. Buchan repaid his nephew by fighting for his cause against rebellious southern barons. Through his marriage to Margaret Ogilvy he acquired the title Lord Auchterhouse.
James Stewart was the second son of Sir James Stewart, the Black Knight of Lorne, and Joan Beaufort, the widow of James I of Scotland. "Hearty James" was a younger brother of John Stewart, 1st Earl of Atholl, and a younger half-brother of James II of Scotland and Princess Margaret Stewart, first wife of Louis XI of France.
In 1467, his nephew James III granted him and his wife the lands of the Baronies of Strathalva and Down, with the Castle of Banff and the fishings of the water of River Deveron. In 1469, James III conferred on James the Earldom of Buchan (first of the third creation). James III conferred the estate of Traquair to William Rogers, an eminent musician, and one of his favourites. After holding the lands for upwards of nine years, Rogers sold them for an insignificant sum, in 1478, to Buchan.
When the southern barons entered into a conspiracy against the King, the Earl of Buchan remained loyal. The King crossed the River Forth, and passed into the northeastern counties, where a strong force rallied around him. He then marched south, and came in sight of the rebellious barons at Blackness in West Lothian, and the Earl of Buchan attacked and drove back the left wing of the insurgent army.
Negotiations were opened, and the Earl of Buchan insisted on severe measures against the insurgent nobles; but George Gordon, 2nd Earl of Huntly and William Hay, 3rd Earl of Erroll were opposed to this, and they retired to the north. It was evident, however, that Buchan's view was right. A pacification was arranged in May 1488, in which the barons promised to return to their allegiance and maintain the rights of the Crown and the peace of the kingdom; and the King disbanded his army and returned to Edinburgh.
However the rebellion continued and on 11 June 1488 at the Battle of Sauchieburn James III and was defeated and killed. The victorious barons passed the night on the field of battle. On the following morning they proceeded to Linlithgow, issued a proclamation, and immediately seized the Royal treasure and the reins of Government. The Earls of Buchan, Huntly, and Lennox, Lord Forbes and others, who had fought for James III, were summoned to appear before Parliament and answer to a charge of treason.
Parliament met at Edinburgh on 6 October 1488, and considered the position of those who had been summoned for treason. The Earl of Buchan tendered his submission; and he was pardoned and restored to power. None of the others who was cited appeared, and consequently their possessions were placed at the disposal of Parliament.
Buchan had several illegitimate children with his mistress Margaret Murray (b. ca. 1446), many of whom were later legitimized by a royal charter issued in 1488-1489.