George, 10th Earl Marischal was a Scottish and Prussian army officer and diplomat. A Jacobite, and last Earl Marischal, he was attained for treason for supporting James II in the rising of 1715 and led the abortive Spanish Jacobite expedition to Scotland in 1719. His appointment by his friend Friedrich II, King of Prussia (Frederick the Great) as Prussian ambassador at Paris caused considerable ill-feeling in England. When ambassador at Madrid in 1758, he informed the English government of Spanish plans to go to war. His loyalty was rewarded by King George II who pardoned Marischal, allowing him to return to his native Scotland and succeed to his estates which included the family seat of Keith Hall, Aberdeenshire. In 1764 he was recalled to Prussia by Friedrich II, where he remained until his death in Potsdam in 1778.
There are several known versions of the present portrait, including those in the Collections of Major J. Drummond-Moray, Abercairny House, and the Scottish National Portrait Gallery. For a detailed discussion, see J. Kerslake, Early Georgian Portraits, London, 1977, pp. 182-183.