Throughout its long history the British and Foreign Anti-Slavery Society was instrumental in framing Britain's diplomatic policy of promoting anti-slavery - a policy that projected moral authority over allies and rivals, through naval power and international tribunals.

The BFASS pushed for and prepared the 1890 Brussels conference that divided Africa between the European powers, on the grounds of fighting Arab slavers. The Society was torn between its belief in the civilising mission of Europeans, and its brief to protect Africans. Rubber slavery in the Belgian Congo, indentured 'coolies' in the Empire, and forced labour in British Africa tested the Society's goals of civilising the world.

This first comprehensive history of the Society draws on 120 years of anti-slavery publications, like the Anti-Slavery Reporter, to explain its unique status as the first international human rights organisation; and explains the Society's surprising attitudes to the Confederate secession, the 'Coolies', and the colonisation of Africa.