Baptised on 14 May 1727 at Sudbury, Suffolk, the son of a clothier. He came to London c. 1740 as a pupil of Hubert Gravelot, before establishing his own studio c. 1745. He practised landscape and portrait painting in Sudbury 1748-52, Ipswich 1752-9, and Bath 1759-74, before finally settling in London. Though his reputation was made by portraiture which owed not a little to van Dyck and Watteau, he was happier painting landscapes, initially in the manner of Wijnants and Ruisdael and later in a more conceptual, personal style.
An impulsive man, he was temperamentally opposed to his admired contemporary, Reynolds; 'Genius & regularity are utter Enemies', he once wrote. A founder member of the Royal Academy, London where he exhibited 1769-72 and 1777-83. He died in London on 2 August 1788 and was buried at Kew, next to his old Ipswich friend, Joshua Kirby.