Slavery in England had already been criminalized in 1102, and the last serfs disappeared in the early 17th century. But from the 18th century, black slaves began to be imported into London and Edinburgh as servants of the British, but the legal status of black slaves at that time was not obtained by trade, and their legal status was always ambiguous. Until 1772, a black slave named James Somerset escaped, and was captured by his master and sent to Jamaica to grow sugar cane. Since Somerset had been baptized in London, his godfather sued the court with a "writ of habeas corpus". The then President of the Throne Court of the High Court of England and Wales ruled on June 22, 1772 that black people should be freed. This declared that slavery did not exist under English law, and that owning slaves was illegal. This sentence freed 10,000 to 14,000 slaves in England.

In 1783, the anti-slavery movement began in British society. In May of that year, the "Abolition of the Slave Trade Committee" was established to crack down on the Atlantic slave trade by British businessmen.

On March 25, 1807, the British Parliament passed the Slave Trade Act, which made it illegal to sell slaves in the British Empire and imposed a fine of 100 pounds sterling on British slave ships. Although the 1807 Act eliminated the slave trade, slavery persisted. In the 1820s, the abolitionist movement became active again. In 1827, the Anti-Slavery Society was formed, many of whom were abolitionists who had participated in the anti-slave trade. The movement aimed to abolish slavery altogether. On August 23, 1833, the Abolition Act outlawed slavery in the British colonies. On August 1, 1834, all slaves under the British Empire were liberated, but they were still required to work for their former masters until 1838 as an adjustment period.