In May 1840 Cox wrote to one of his Birmingham friends: "I am making preparations to sketch in oil, and also to paint, and it is my intention to spend most of my time in Birmingham for the purpose of practice". Cox had been considering a return to painting in oils since 1836 and in 1839 had taken lessons in oil painting from William James Müller, to whom he had been introduced by mutual friend George Arthur Fripp. Hostility between the Society of Painters in Water Colours and the Royal Academy made it difficult for an artist to be recognised for work in both watercolour and oil in London, however, and it is likely that Cox would have preferred to explore this new medium in the more supportive environment of his home town. By the early 1840s his income from sales of his watercolours was sufficient to allow him to abandon his work as a drawing master, and in June 1841 he moved with his wife to Greenfield House in Harborne, then a village on Birmingham's south western outskirts. It was this move that would enable the higher levels of freedom and experimentation that were to characterise his later work.