William Turner is one of the most renowned and acclaimed British painters. The Tate Britain, for instance, is significantly dedicated to him. He will be the face of the £20 note starting 2020.
He belongs to the romantic movement, with a style that favours the tempestuous, the emotionally overloaded and the explosion of space in which are trapped little, insignificant, undignified sketches of characters. This makes a break with the traditional style of his time. One can compare the crossing of the Alps according to David (for Napoléon) and according to Turner (for Hannibal). In one case, a glorified portrait of man, dompting his horse, where the Alps could even not enter the picture; in the other, a storm of darkness and light, overtaking minuscule figures, where the Alps struggle to enter the picture.
Turner influenced in particular impressionists. He was indifferent to posterity and chose materials that looked good when freshly applied.