William Prinsep belonged to a large and well-known Anglo-Indian family, which produced a number of artists. His father John Prinsep of the East India Company, often regarded as the founder of the indigo trade in India, had seven sons, all of whom followed him to India as traders, lawyers or civil servants. William, the fifth son, worked for the House of Palmer & Co., bankers and merchants, in Calcutta, as did his younger brother, George. He took lessons in painting from George Chinnery and was a prolific amateur artist, painting landscapes, figures and the grand architecture of Calcutta, as well as recording a return journey to England in 1842 in a fascinating series of watercolours. William was in fact the most accomplished of all the watercolourists in the family, although not the most famous artist. This was Val Prinsep, son of William's elder brother Henry Thoby Prinsep, who was to become a Royal Academician and succeed Herkomer as Professor of Painting at the R.A. in 1900.