Patrick succeeded to the title of 8th Earl of Dunbar on 10 October 1308. He succeeded to the title of 2nd Earl of March on 10 October 1308. In 1314 he was initially pro-English, playing host at Dunbar Castle to the defeated King Edward II after the rout of Bannockburn and facilitating his escape back to England. He held the office of Sheriff of Lothian before 1318. In 1318 he supported Scottish independence and helped take Berwick. In September 1320 married a second time to Agnes Randolph (known as ‘Black Agnes'.) He fought in the Battle of Dupplin in 1332, where he commanded Scottish troops. He fought in the Battle of Halidon Hill in 1333, where he commanded Scottish troops. After 1333 he again went over to the English but after a year or so ratted on them a second time. He fought in the Battle of Neville's Cross in 1346, where he commanded the Scottish left wing. He was created 1st Earl of March and Moray [Scotland] in 1357/58. In February 1360/61 he appears to have deserted the Scots Crown yet a third time since he is called a rebel and his lands are pronounced forfeited. On 25 July 1368 he resigned his earldoms of Dunbar and of March, with a regrant to his great-nephew and heir male, George de Dunbar. On his death, his Earldom of March and Moray appears to have reverted to the Crown. He died on 11 November 1368, without surviving male issue.
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