The Slavery Abolition Act received Royal Assent on 28 August 1833. It was a major change in British law, but it did not immediately free everyone enslaved across the British Empire.

Parliament had prohibited the British slave trade in 1807. Slavery itself continued in British colonies, including the Caribbean, where plantation economies remained dependent on enslaved labour.

Pressure for abolition continued through campaigning in Britain and resistance by enslaved people. The Baptist War in Jamaica in 1831–32, a large uprising involving tens of thousands of enslaved people, added to political pressure on the system.

The legislation passed in 1833 provided for slavery to become unlawful across much of the British Empire from 1 August 1834. Children under six covered by the Act became free. For many older people, however, slavery was replaced by compulsory apprenticeship.

Under apprenticeship, formerly enslaved people were legally reclassified but remained required to work for their former owners for much of the working week without wages. The system was presented as a transition towards freedom while preserving a substantial part of the labour previously claimed by slave owners.

Parliament also authorised £20 million in compensation for those losing their legal claims over enslaved people. The money went to slave owners. The people who had been enslaved received no equivalent compensation.

The apprenticeship system became increasingly controversial. It was ended in the British Caribbean on 1 August 1838, earlier than originally intended for some apprentices.

The date of 28 August 1833 marks Royal Assent rather than immediate emancipation. The Act established the legal machinery for abolition across much of the Empire; however, freedom came later and under terms that protected the financial and labour interests of former slave owners.