"John Sell Cotman was born in Norwich, the son of a shopkeeper who turned from hairdressing to haberdashery. He came to London to further his artistic education in 1798, and soon became a leading member of the circle of watercolour artists gathered around Thomas Girtin (1775-1802), despite having little formal training. Soon after 1804 he returned to Norwich, where he became a popular teacher with a huge 'circulating library' of his art for his students to use in their studies.
Cotman's popularity surpassed Turner's for most of the twentieth century. He was appointed Drawing Master at King's College School in London (1834) and made a final visit to Norfolk in the autumn of 1841, not long before his death in London in July 1842."
—British Museum (.org) John Sell Cotman (.pdf)
Watercolor Masters: John Sell Cotman © 2010 Greg Conley
js cotman article by terry fenton
wikipedia: John Sell Cotman