Morier was a Swiss military and sporting painter who started working for William Augustus, Duke of Cumberland (1721-65) in 1747, when he painted a series of pictures of troops under his command. From 1752 until 1764 he was employed as ‘limner’ (painter) to the Duke on an annual salary of £100; his name also appears regularly in royal accounts from 1764 to 1767. Frederick the Great is shown mounted on a galloping roan charger, wearing a military uniform with scarlet facings and a tricorne hat and the riband and star of the Order of the Black Eagle.