Boys moved to Paris in the early 1820s and became a friend and pupil of Richard Parkes Bonington (1802–1828). He exhibited a large number of watercolours in Paris in the 1830s and is deemed to have made an important contribution to the revival of watercolour painting in France. Boys made several visits to Belgium in the late 1820s and 1830s and was in Brussels during the Belgian Revolution of 1830. His wife Célestine was Belgian, her home either in or near Soignies. His Picturesque Architecture in Paris, Ghent, Rouen etc., was published in 1839.