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.

A full-length Black trumpeter, mounted on a grey horse, in a landscape, blowing his trumpet; he wears a crimson state coat embroidered with the crown and cypher of George II; a tower and an arched building are in the left background.