As early as the ninth century, an Irish chronicle referred to ‘blue men’ (Old Irish, fir gorma) being brought in Viking longships to the British Isles from Morocco, and apparently settling for a while in Ireland. This strange description is still used in the Sahara and derives from the deep blue indigo dye used to colour the voluminous cotton garments worn by such peoples as the Tebisti and Tuareg of North and West Africa, and in regions as far south as northern Nigeria. These garments, known as taubs in Nigeria, often coloured the skin of the wearer, hence the legend of the blue men. These early blue-clad African voyagers, few in number, can hardly be considered the beginning of a continuum of seafarers of African descent on British ships, but they nevertheless provide an evocative portent of the many black sailors who would serve Britain so well in the future, both in times of peace and in her hour of need.

Black Salt: Seafarers of African Descent on British Ships documents the history of seafarers of African descent over several centuries. It examines their work and experience in the British merchant and Royal navies, from impressed slaves to free Africans, British West Indians and also those African Americans who served on British ships prior to the independence of the American Colonies. The book examines the contribution made by both ordinary and extraordinary black seafarers, from the earliest contact between Europeans and Africans to Britain's modern navy, focusing upon the lives of servicemen who did not always achieve recognition, but who nevertheless made Britain great. The voices of black seamen are traced through documents dating back to as early as 1547. Readers will embark upon a journey that allows them to witness at first hand the verbal testimony of black seamen such as Jacques Francis, an African diver who gave evidence in court on the reclamation project that followed the sinking of King Henry VIII's ship, the Mary Rose. Other voices of early black sailors include that of Olaudah Equiano, who served aboard ship on the Phipps Expedition to the Arctic alongside the teenage Nelson. Black Salt avoids an overdependence upon more recent cliometric, quantitative techniques or an outdated anthropological approach to the study of black people.