Reduction of Lagos

The Reduction of Lagos or Bombardment of Lagos was a British naval operation in late 1851. The Royal Navy bombarded Lagos (in present-day Nigeria) in order to suppress the Atlantic slave trade, and to depose the King (Oba) of Lagos, Kosoko, for refusing to end the slave trade.

Many intersecting interests provided the British Government with military action pretext against Kosoko. These interests included the British government's desire to replace the slave trade with alternative legitimate trade, British missionary interest in spreading Christianity, and fears that some Lagos residents, known as the Saro, who were liberated from Atlantic slave trade, would be persecuted and re-enslaved.

The British eventually deposed Kosoko. They replaced him with Akitoye, who had previously lost his throne to Kosoko and had asked the British to help him return to power. In return, Akitoye promised to end the slave trade. In 1852, Akitoye and John Beecroft signed the Treaty Between Great Britain and Lagos.

The treaty required the native ruling elite of Lagos to abolish the Atlantic slave trade, liberate enslaved Africans, expel European slave traders residing in Lagos, and to allow British subjects to have trade access to Lagos. However, illegal slave-trading activities persisted until the British Empire annexed Lagos as a British protectorate in August 1861, which would later be declared a British colony in 1862, and then incorporated into the Southern Nigeria Protectorate in 1906.