Douglas, William, 1st earl of Douglas and Mar, 1327?–1384, Scottish nobleman; nephew of Sir James de Douglas, lord of Douglas. About 1348 he returned to Scotland from France and recaptured the Douglas lands from the English. Later he took part in the negotiations for the ransom and release of David II. In 1354 he succeeded to the estates of his father and uncle and to the lands of his kinsman, William Douglas, Knight of Liddesdale, whom he had slain. Douglas engaged in French-incited raids on the English border and fought (1356) for the French in the battle of Poitiers. In 1358 he was made earl of Douglas, and after the accession of Robert II he was made justiciar S of the Forth and received the lands of the earl of Fife. At the death of his wife's brother in 1374 he received the lands and title of the earl of Mar. Douglas had an illegitimate son by Margaret Stuart, countess of Angus in her own right. This was George Douglas, who became 1st earl of Angus.