In 1469 the earldom was conferred on James Stewart. He was made Lord Auchterhouse at the same time, also in the Peerage of Scotland. Stewart was the second son of Sir James Stewart, the Black Knight of Lorn, and the younger brother of John Stewart, 1st Earl of Atholl (see Earl of Atholl, 1457 creation). The title descended in the direct male line until the death of his grandson, John, the third Earl, in 1551. John's only son by his first marriage, John Stewart, Master of Buchan, had been killed at the Battle of Pinkie in 1547. Buchan was therefore succeeded by his granddaughter, Christina, "suo jure" Countess of Buchan, the daughter of the Master of Buchan. She married Robert Douglas, son of Sir Robert Douglas of Lochleven and brother of William Douglas, 6th Earl of Morton. Robert assumed the title of Earl of Buchan in right of his wife. He was succeeded by his daughter, Mary, "suo jure" Countess of Buchan. She married James Erskine, younger son of John Erskine, Earl of Mar. James assumed the earldom in right of his wife. In 1617 they were created by Royal charter Earl and Countess of Buchan, with remainder to the heirs male of the marriage, whom failing, to the legitimate and nearest heirs-male and assignees of the Earl. In 1633 the precedence of the earldom was established by Act of Parliament as 1469. This line of the family failed on the death of their grandson, the eighth Earl, who died unmarried in 1695. The title passed by the terms of the 1617 charter to the heirs male of the 6th Earl i.e. to the heirs male of his younger brother Henry Erskine (see below). Since 1695, the earls of Buchan are not heirs of line of the 1st Earl of Buchan.