Rossetti was the engine of the Pre-Raphaelite Brotherhood. He co-founded it in 1848 with Holman Hunt and John Everett Millais, writing the manifesto, recruiting members, and generating the intensity that held the group together. He was nineteen. The name was deliberately provocative: they wanted to reject everything after Raphael, which was most of Western art.

He was born in London to an Italian political exile and named after the author of the Divine Comedy. His father was a professor of Italian at King's College. The household ran on poetry, politics, and argument. Rossetti wrote verse throughout his life and considered himself a poet as much as a painter.

His early paintings are small, bright, and meticulously detailed in the Pre-Raphaelite manner. The Girlhood of Mary Virgin and Ecce Ancilla Domini have the flat, jewelled quality of medieval altarpieces. After 1860 the style changed. The paintings became larger, more sensual, and dominated by the face and figure of Jane Burden, who was William Morris's wife.

The relationship between Rossetti, Morris, and Jane is one of the more uncomfortable triangles in art history. Morris married her. Rossetti painted her obsessively. She modelled for Proserpine, La Pia de' Tolomei, and dozens of other works in which she appears as a mythological woman trapped in an unwanted situation. Whether the affair was physical remains debated. Morris, characteristically, said nothing publicly and channelled his feelings into wallpaper.

Rossetti buried a manuscript of his poems in his wife Lizzie Siddal's coffin when she died of a laudanum overdose in 1862. Seven years later he had the coffin exhumed to retrieve them. He published the poems. He was addicted to chloral hydrate by then and increasingly paranoid. He died in 1882, at fifty-three.