An act of Parliament abolished slavery in the United Kingdom in 1833. It was the result of determined effort by many, black and white.

Slavery was an established institution in the British Empire from the 17th Century. Slavery could be found in the North American colonies, in the Caribbean, in South America, and elsewhere, but had been absent from British shores since 1772.

In May of that year, a judgement in what has come to be called Somersett's Case resulted in an English judge's declaring that English common law had no provision for keeping anyone enslaved; as a result, enslaved African James Somerset was set free.

As in the United States, members of the Quaker religion played a major role in the movement to abolish slavery. In 1783, a group of British Quakers began distributing pamphlets advocating abolition to both the public and to members of Parliament.

One well-known abolitionist in the U.K. was former Olaudah Equiano. He was one of the rare slaves whose masters paid their slaves, and Equiano saved up enough money to buy his freedom. He traveled to several countries and then settled in England. He became a member of the Sons of Africa, a group of black Africans who spoke out against slavery, and in 1789 published his autobiography, The Interesting Narrative of the Life of Olaudah Equiano or Gustavus Vassa, the African, which sold very well and made more well-known the horrors of slavery.

One of the main drivers of the abolition movement in the U.K. was William Wilberforce. As early as 1789, he was delivering impassioned speeches in public, calling attention to the horrors of slavery. On May 12 of that year, he spoke for three hours in front of Parliament.

War with France, beginning in 1792, captured the people's attention, and so the abolition movement had to wait. Wilberforce returned each year to Parliament, introducing a new bill in hopes of getting it passed. He succeeded in winning enough support in 1807, and the Slave Trade Act 1807 officially abolished the slave trade throughout the British Empire, as of Jan. 1, 1808.

That didn't end slavery entirely, however, and Wilberforce and others continued the campaign, targeting anew the smuggling that was still occurring. Another leader of the abolition movement in the U.K. was Henry Brougham, whose efforts included getting into Parliament and then getting Parliament to enact the Slave Trade Felony Act 1811, which did what its name suggests. This act also put some muscle into enforcement, providing for the Royal Navy's West Africa Squadron, which from 1808 to 1960 captured 1,600 slave ships and freed 150,000 Africans intended to be slaves.

Brougham, Wilberforce, and others founded the Anti-Slavery Society in London in 1823. Support for abolition grew in the next few years and grew even more after the Baptist War, a Jamaica slave revolt in which about one-fifth of the 300,000 slaves in Jamaica. British soldiers got involved in ending the revolt. The reaction from the Jamaican slave owners was far more violent, and news of this hastened Parliament's consideration of yet another abolition bill by Wilberforce.

Finally, in 1833, the British Government passed a law abolishing slavery. Both the House of Commons and the House of Lords passed the bill, and it became law with the required Royal Assent on Aug. 28, 1833. By the terms of the bill, it came into effect nearly a year later, on August 1, 1834. The effect was neither immediate nor absolute. Those who had been enslaved and under 6 years of age were instantly free. Anyone who had been enslaved but over 6 were suddenly termed "apprentices," whose "service" was ended either in 1838 or in 1840, depending on a set of rules drawn up by Parliament. And the Slavery Abolition Act 1833 specifically excepted slavery in territories owned by the East India Company. As well, the Government agreed to compensate slave-owners for the sudden loss of income.

Wilberforce didn't live to see his victory take effect. He died two days after the bill's passage.