the patronage of Cavers, in procuring the release of Mercer, a merchant of Perth taken prisoner on the coast of Northumberland, and in various transactions as warden of the marches. About 1374 he added to his already vast possessions in the south the territory and title of the Earl of Mar, through his wife Margaret, sister of Thomas, thirteenth earl of Mar, to whom he had been married in 1357. She was his only wife, for the other two assigned to him by Hume of Godscroft have no place in authentic records. The countess survived him, and the hypothesis of her divorce is without foundation. It was keenly disputed in the litigation for the peerage of Mar between the Earl of Kellie and the Earl of Mar (Mr. Goodeve Erskine) whether the Earl of Douglas took the title of Mar in his own right or in that of his wife. But as no grant of the Mar title to him is on record the inference is that he succeeded, according to the custom of Scotland, in right of his wife, who was the heir of her brother, who died childless. This inference does not seem overcome by the fact that he is styled Earl of Douglas and Mar, not of Mar and Douglas, or that his seal gave the first and fourth quarters to his own Douglas arms in preference to those of Mar, which are placed on the less honourable second and third quarters. Although the Mar title was the most ancient, being the premier earldom of Scotland, it was natural that Douglas should prefer to retain that of his own family, which had been conferred on himself in the first place in his designation and arms.
The closing years of the earl's life were occupied with border raids. In one of these, related by Froissart, he defeated and took prisoner Sir Thomas Musgrave, the commander of the English force at Melrose, in an engagement which was the sequel of the capture of Berwick by the Scots, who held it only nine days, when it was retaken by the Earls of Northumberland and Nottingham and Sir Thomas Musgrave. The date of the capture of Berwick was, according to Walsingham, 25 Nov. 1378, which would place the engagement between Douglas and Musgrave in the end of that or the commencement of the next year. This appears the most probable account, although the Scottish historians, Wyntoun and Bower, place Musgrave's defeat in 1377, and assign the credit of it to a vassal of the Earl of March, and not to Douglas. In the spring of 1380 Douglas headed a more formidable raid into England, in retaliation for the invasions of the Earl of March's lands on the Scottish borders by Northumberland and Nottingham. His troops are said on this occasion to have numbered twenty thousand men, and after carrying away great booty—as many as forty thousand cattle—from the forest of Inglewood, and ravaging Cumberland and Westmoreland, Douglas burnt Penrith. He was afraid, however, to attempt the siege of the strong castle of Carlisle, and returned to Scotland. Though successful in its immediate object, this incursion cost the Scots more than they gained, by introducing the pestilence from which the English were then suffering. On 1 Nov. 1380 Douglas, along with the bishops of Glasgow and Dunkeld, and his kinsman, Sir Archibald Douglas, lord of Galloway, was present at Berwick, where John of Gaunt met them and negotiated a truce to last till 30 Nov. 1381. The young Richard II was threatened by the rising of the peasants under Wat Tyler. John of Gaunt, who was specially aimed at by the insurgents, was soon after obliged to take refuge in Edinburgh, where he was hospitably received and remained till July 1381. Douglas and Sir Archibald were sent to conduct him from Ayton, where he had met the king's son John, earl of Carrick, and prolonged the truce till Candlemas 1384, to the Scottish capital, and perhaps took part also in re-escorting him to Berwick. Between 1381 and 1384 Douglas, now far advanced in years, was constantly in attendance on the king, who, as usual in these times, was travelling over his kingdom. He is shown by various charters to which he was a party or a witness to have been at Wigton in September 1381, at Edinburgh in October, and later in Ayrshire, where he remained till the following spring. In 1383 he was at Stirling and Dundee, and on 18 Jan. 1384 at Edinburgh. Almost immediately after the expiry of the truce hostilities were resumed on both sides of the border, and Douglas received a special commission from the king for the reduction of Teviotdale, where many of the inhabitants still refused to accept the Scottish allegiance. His satisfactory execution of this commission was the last act of his life, and in May 1384 he died of fever at Douglas, and was buried at Melrose. Besides his successor, James, he left a daughter Isabella, who succeeded after her brother's death to the unentailed lands of Douglas and the title and lands of Mar. This lady married, first, Malcolm Drummond, brother of Annabella, the wife of Robert III, and, second, Alexander, son of Alexander Stewart, earl of Buchan. He had also two illegitimate children, George, afterwards first earl of Angus, of the line of Douglas [q. v.], by Margaret Stewart, sister and heir of Thomas, third earl of Angus, and wife of Thomas, thirteenth earl of Mar, and Margaret, who married Thomas Johnson, from whom probably
