Thomas Beach studied with Joshua Reynolds from 1760 until early in 1762, during which time he was also a student at the St. Martin's Lane Academy, London. He probably settled in Bath; his recorded portraits of the 1760s are all of sitters from Dorset or Somerset, and he sent two portraits from an address in Bath to the Society of Artists exhibition of 1772. He exhibited with the Society until 1783, becoming its vice-president (1782) and president (1783) he also exhibited at the Royal Academy (1785-90, 1797). He probably divided his mature practice between London and Bath.
His early reliance on Reynolds' ideas of propriety gave way to a more direct approach, seen at its best in group portraits such as the present work, The Stapleton Family (1789; Holburne Museum, Bath) and A Group portrait of the Craven Children (Christie's, London, 18 April 1996, lot 13). In the present work the influence of Zoffany's conversation pieces can be seen as well as the informality of Romney's group portraits of children. The theatrical element in Beach's work, reflecting his interest in the stage, is seen most strikingly in Sarah Siddons and John Philip Kemble in Macbeth Act 2, Scene ii (1786; Garrick Club, London). Beach's diary for 1798, the only one to have survived, chronicles what appears to have been an annual tour of the west country; that year he completed thirty-one portraits between June and December. The fact that Beach was able to capture a strong likeness was enough to establish his reputation as fashionable portrait painter in provincial circles. His last recorded work is a Self-portrait (1802; National Portrait Gallery, London) but he painted little after 1800 and retired to Dorchester.