as a Whig in 1761 and was elected to two seats. He chose to give up Wigtown Burghs to sit in the seat for Ayrshire, and served in the House of Commons from 1761 to 1768. In 1761, Montgomerie became an Equerry for Queen Charlotte. He was appointed Governor of Dumbarton Castle in 1764 and Deputy Ranger of St. James's Park and Deputy Ranger of Hyde Park in 1766. On 24 October 1769, Montgomerie's brother, Alexander Montgomerie, 10th Earl of Eglinton, was murdered by Mungo Campbell, after a dispute on whether or not Campbell could bear arms on the 10th Earl's property. The 10th Earl died in the early morning hours of 25 October 1769, and Montgomerie inherited the Earldom. He was Grand Master of the Masonic Lodge of Mother Kilwinning, from 1771 until 1796. Montgomerie was elected as one of sixteen Scottish representative peers in 1776 and was re-elected in 1780, 1784, and 1790. Montgomerie was appointed Governor of Edinburgh Castle, in 1782, and served as Lord Lieutenant of Ayrshire between 1794 and 1796. Montgomerie was also the patron to the poet Robert Burns; Burns and Montgomerie kept in contact until the latter's death. Montgomerie died on 30 October 1796 at Eglinton Castle. The Earldom passed to a third cousin, Hugh Montgomerie, 12th Earl of Eglinton. However, the majority of Archibald Montgomerie's wealth went to his daughter Mary, whose son eventually became the 13th Earl of Eglinton. There is a portrait of Montgomerie in Windsor Castle. It was offered back to the family by King William IV, but the 13th Earl declined. He felt that it was an honour to have a portrait of his grandfather at Windsor Castle. Personal life Montgomerie was married twice. He was first married, to Lady Jean (Jane) Lindsay, who was the daughter of George Lindsay-Crawford, 21st Earl of Crawford and Lady Jean Hamilton, on 30 March 1772. Jean died in 1778 without issue. On 9 August, 1783, Montgomerie married Frances Twysden, the daughter of Sir William Twysden, 6th Baronet and Mary Jervis, has his second wife. They divorced on 6 February 1788 on account on her affair with Douglas Hamilton, 8th Duke of Hamilton with whom she allegedly had a daughter. He and Frances had two children: Lady Mary Montgomerie (5 March 178712 Jun 1848). Mary was married to Lord Hugh Montgomerie. Their son, Archibald Montgomerie, 13th Earl of Eglinton, would eventually succeed