In the only known painted portrait of Mary Seacole, lost until 2003, the sitter looks to her right, her face turned almost haughtily away, as if defying viewers to define her. In her memoirs, Wonderful Adventures of Mrs Seacole in Many Lands, published in 1857, she is equally elusive. During her lifetime, the Jamaican-born daughter of a free black woman and a white Scottish soldier was as famous for her work tending to the sick and wounded in the Crimean War as Florence Nightingale. Yet key details of her life have remained obscure, partly as a result of her own efforts to omit or cloud significant facts.

Helen Rappaport, who identified the portrait after it was found in a car boot sale and presented it on loan to the National Portrait Gallery, has spent twenty years unravelling the enigma of Mary Seacole. Best known for her scintillating books on the Russian Revolution, Rappaport has doggedly scoured archives and unearthed records like a terrier worrying at a bone. Her book, the fruits of that research, is not only an account of Seacole’s life but also a record of the author’s journey of discovery, as much detective story