Thomas Cochrane , 8th Earl of Dundonald Thomas Cochrane , 8th Earl of Dundonald ( 1691 – 31 October 1778 ) was a Scottish nobleman , army officer and politician . He was Member of Parliament for Renfrewshire , 1722 - 1727 . He served as Commissioner of the Excise for Scotland from 1730 until 1764 . He acceded to the title of Earl of Dundonald in 1758 on the death of his cousin , William Cochrane , 7th Earl . Early life and education . Thomas was born in 1691 , the seventh son of William Cochrane of Ochiltree , and his wife Lady Mary Bruce , eldest daughter of Alexander Bruce , 2nd Earl of Kincardine . As a younger son , he would not inherit his father ' s property , so he entered the army . He became a cornet in the Royal Regiment of Dragoons in 1713 , and a captain in the 27th Regiment of Foot in 1716 . He rose to the rank of major in 1718 and was Fort Major at Fort St Philip on Minorca . He became Member of Parliament for Renfrewshire in 1722 , and represented the constituency until 1727 . He was appointed as Commissioner of the Excise for Scotland from 1730 until 1764 . He supported the Hanoverians during the Jacobite Rising of 1745 . He later gave evidence in court against the Archibald Stewart , Lord Provost of Edinburgh , who had surrendered the city to the Jacobites . Thomas Cochrane acceded to the title of Earl of Dundonald on the death of his cousin , William Cochrane , the seventh earl , on 9 July 1758 . William , an army officer , had been killed at the Siege of Louisbourg , and died without issue . As the eldest surviving son by then of William Cochrane of Ochiltree , Thomas had already inherited the family estates at Culross and Ochiltree . Family and issue . Cochrane was married twice , firstly to his cousin , Elizabeth Kerr , in 1721 . They had two children , a son Thomas who died young , and a daughter Grizel . Elizabeth died in 1743 . On 6 September 1744 , Cochrane married Jane Stuart . They had a number of children , firstly Archibald , born in 1748 , who became an inventor and succeeded his father in the earldom , and secondly Charles , born in 1749 . He had an army career . Charles married Catherine Pitcairn , the daughter of Major John Pitcairn . He distinguished himself during the American War of Independence by carrying despatches from Sir Henry Clinton to Lord Cornwallis at the Siege of Yorktown . Cornwallis made him his aide de camp . Charles Cochrane was killed shortly before the surrender . Thomas and Jane Cochrane ' s third son , John , was born in 1750 , and their fourth , James Atholl , was born in 1751 . He entered the church , becoming vicar for Mansfield . Their fifth son Basil was born in 1753 . He made a fortune supplying the Royal Navy in India . Their sixth son Alexander Forrester Inglis was born in 1758 , and entered the Royal Navy . He rose to be admiral of the white , an MP , and a Knight Grand Cross of the Bath . Their seventh son George Augustus Frederick was born in 1762 . He joined the army , reaching the rank of colonel and was an MP . Their eighth and youngest son Andrew James was born in 1767 . He also served in the army , reaching the rank of brigadier , sat as MP for several constituencies , and was Governor of Dominica . Less honourably , he was indicted for his role in the Great Stock Exchange Fraud of 1814 . Andrew ' s nephew , the prominent naval officer Thomas Cochrane , Lord Cochrane , was also convicted in this case , but years later received a royal pardon . Thomas Cochrane died on 31 October 1778 . He was succeeded in the earldom by his eldest son Archibald , who became the 9th Earl of Dundonald .