These feuds were followed by a formidable insurrection, or more correctly, invasion, in 1411, by Donald, Lord of the Isles, of such a serious nature as to threaten a dismemberment of the kingdom of Scotland. The male succession to the earldom of Ross having become extinct, the honours of the peerage devolved upon a female, Euphemia Ross, wife of Sir Walter Lesley. Of this marriage there were two children, Alexander, afterwards Earl of Ross, and Margaret, afterwards married to the Lord of the Isles. Earl Alexander married a daughter of the Duke of Albany. Euphemia, Countess of Ross, was the only issue of this marriage, but becoming a nun she resigned the earldom of Ross in favour of her uncle John Stewart, Earl of Buchan. The Lord of the Isles conceiving that the countess, by renouncing the world, had forfeited her title and estate, and, moreover, that she had no right to dispose thereof, claimed both in right of Margaret his wife. The Duke of Albany, governor of Scotland, at whose instigation the countess had made the renunciation, of course refused to sustain the claim of the prince of the islands. The Lord of the Isles having formed an alliance with England, whence he was to be supplied with a fleet far superior to the Scottish, at the head of an army of 10,000 men, fully equipped and armed after the fashion of the islands with bows and arrows, pole-axes, knives, and swords, in 1411 burst like a torrent upon the earldom, and carried everything before him. He, however, received a temporary check at Dingwall, where he was attacked with great impetuosity by Angus Dubh Mackay of Farr, or Black Angus, as he was called; but Angus was taken prisoner, and his brother Roderic Gald and many of his men were killed. Flushed with the progress he had made, Donald now resolved to carry into execution a threat he had often made to burn the town of Aberdeen. For this purpose he ordered his army to assemble at Inverness, and summoned all the men capable of bearing arms in the Boyne and the Enzie, to join his standard on his way south. This order being complied with, the Lord of the Isles marched through Moray without opposition. He committed great excesses in Strathbogie and in the district of Garioch, which belonged to the Earl of Mar. The inhabitants of Aberdeen were in dreadful alarm at the near approach of this marauder and his fierce hordes; but their fears were allayed by the speedy appearance of a well-equipped army, commanded by the Earl of Mar, who bore a high military character, assisted by many brave knights and gentlemen in Angus and the Mearns. Among these were Sir Alexander Ogilvy, sheriff of Angus, Sir James Scrymgeour, constable of Dundee and hereditary standard-bearer of Scotland, Sir William de Abernethy of Salton, nephew to the Duke of Albany, Sir Robert Maule of Panmure, Sir Alexander Irving of Drum, and Sir Robert Melville. The Earl was also joined by Sir Robert Davidson, the Provost of Aberdeen, and a party of the burgesses.