Those who know Turner (1775-1851) by his marvellous Ashmolean pictures of Oxford High Street and the Thames may think that he was a great realist painter.

But they were early works, done when he was in his thirties. The extraordinary late paintings of clouds, storm, waves and light which you can see in Tate Britain convinced many people that he was mad.

He came from a quite ordinary background, a barber’s son, and was educated by the Royal Academy.

He was eccentric and had gruff manners. “The man must be loved for his works, for his person is not striking, nor his conversation brilliant,” someone said.

From childhood he was always sketching, or travelling over Britain and Europe to discover landscapes. His figures are less well drawn, because his interest in human beings was minimal. “I hate married men,” he allegedly said, “they never make any sacrifices to the arts.” He didn’t get married himself, although he had two daughters (in whom he took little interest) from a ten-year relationship. He left his pictures, many unsold at his death, to the nation.

Standing in the Sun, an admirable biography by Anthony Bailey, was first published in 1997 and has been reissued by the Tate, perhaps because of the major exhibition now at the National Maritime Museum in Greenwich. The illustrations are in black and white.