International rescue

In 1807 the Slave Trade Act was passed, making the slave trade illegal throughout the British Empire. The statutory manumission of slaves within British possessions would follow in the Slavery Abolition Act 1833.

The Royal Navy was the means by which the 1807 Act was to be upheld, with British ships forming the bulk of the West Africa Squadron. This was officially a multi-national force, and ships from Prussia, the Netherlands and Portugal assisted the Royal Navy. The United States constituted the African Slave Trade Patrol in 1819, despite slavery remaining an integral feature of southern American life until the 1860s.

In parallel with her military endeavours, Britain used her post-Napoleonic power to press for diplomatic suppression of slavery. Over 30 treaties were entered into, covering all of the major Atlantic powers (Portugal, Spain, France and the Netherlands), some distinctly non-maritime powers (Austria and Prussia) and many small countries (Sardinia, Naples and Tuscany).

All of this added legal and diplomatic complexities to the practical difficulties of the West African Squadron. Rule books were provided to Captains detailing treaties in effect with various countries, and outlining the rights of inspection, search and seizure.

All of this combined with miserable conditions adrift the hostile, pestilent and humid African coast. Violent clashes with well armed slavers added to mortality rates that were nearly six times that of the Royal Navy’s Mediterranean patrols.

Whilst some sailors and commanders had humanitarian or religious reasons for enduring their harsh regime, the prospect of prize money for captured ships and ‘head money’ for freed slaves also made duties more bearable. According to Jan Morris in Heaven’s Command, this amounted to £5 per head if the freed slave was alive and £2.10s if they were dead.

• Heaven's Command: An Imperial Progress (Pax Britannica)