From Wikipedia

George Stubbs

(August 25, 1724 - July 10, 1806)
was a British painter, best known for his paintings of horses.
Stubbs was born in Liverpool, the son of a currier and leather merchant. Information on his life up to age thirty-five is sparse, relying almost entirely on notes made by fellow artist Ozias Humphry towards the end of Stubbs's life. Stubbs worked at his father's trade until he was 15 or 16, and after his father's death in 1741 was briefly apprenticed to a Lancashire painter and engraver named Hamlet Winstanley. He soon left as he objected to the work of copying to which he was set. Thereafter as an artist he was self-taught. In the 1740s he worked as a portrait painter in the North of England and from about 1745 to 1751 he studied human anatomy at York County Hospital. He had had a passion for anatomy from his childhood, and one of his earliest surviving works is a set of illustrations for a textbook on midwifery which was published in 1751.