Zucarelli was right. After 5 years in Italy, Wilson returned home to become the first great landscape painter of Britain. His paintings were in the traditional 'Grand manner', with carefully balanced compositions and classic-style figures in the foreground in a technique inspired by Claude Lorrain. Yet, Wilson's colour sense was superior to that of any of his contemporaries, and he painted much more what he saw, despite the constrictions of a Classical rather than a natural landscape. His honest attempts at realism may be thought of as one of the earliest moves towards the 'truth to nature' of the Pre- Raphaelites in the next century.
Wilson returned to London in the mid-1750s, took a house in Covent Garden, and established himself with the picture Niobe (1760), sent to the first exhibition of the Society of Artists. He was one of those involved in the setting up of the Royal Academy, and attained the position of Librarian at that institution.
Despite his reputation among artists, both in England and abroad, Wilson's works were not popular with the public or the moneyed classes who bought paintings. Gradually he became poorer, until many of his pictures went straight from the easel to the pawnbroker. He had to leave his fine house for successively more and more modest accommodation, until at last he had only a meagre flat in Tottenham Court Road. Once, a young Academy student brought to him a noble lady, who commissioned two paintings. When she left, Wilson thanked the student, but said that his kindness was in vain, for he had no money to buy proper canvas and colours for the paintings. The student gave Wilson 20 pounds, and himself abandoned painting for the security of a career as a churchman, saying that "When Wilson with all his genius starves, then what will become of me?"
In the end, Wilson was rescued from poverty by an inheritance of land and a lead mine, back in his home place of Denbighshire. He left London, returning to his roots, but survived only a brief period before dying while out on a walk, aged 69.