Grimm was the son of a Swiss notary at Burgdorf, about fifteen miles from Berne. At Berne, his uncle, Johann, a painter of miniatures and watercolors, had a drawing school that was taken over after his death by Johann L. Aberli, well-known for his color prints of Swiss scenery. It was to Aberli that the young Hieronymous went as a pupil. From 1758 onwards young Grimm was writing poetry and making drawings of Swiss views. In 1765 he went to Paris for a stay of three years, and in 1768 began the third stage of his roving life. For twenty-six years Grimm went to and fro in the his adopted Britain, ceaselessly making drawings.
In England Grimm began by showing four works at the first exhibition of the Royal Academy in 1769, exhibiting there until 1784, and at the Free Society of Artists until 1793. Most of his works are topographical views in pen, pencil, and watercolor, of which he produced a vast number for such private patrons as Sir William Burrell, Sir Richard Kaye, H.P. Wyndham, and Gilbert White of Selborne. The artist's humor appears in his caricatures of Georgian Men and manners and in political satires. He found other topics, where his interest in figures and costume had full play -- a city fire, a country fair, ceremonies attended by royalty, the Montem pageant at Eton, military reviews, camps in the park, or an election celebration. But perhaps his most attractive work is in his simple rural subjects, with slight figure incident, delicately drawn and daintily stained with color. Grimm died at his residence in Tavistock street, and was buried in St. Paul's Church, Covent Garden. (extracted from Martin Hardie, Water-colour Painting in Britain, vol. 1 (New York, 1966), 164-166.)