The Society for the Abolition of the Slave Trade was principally a Quaker society founded in the eighteenth century by Thomas Clarkson. The slave trade had been abolished throughout the British Empire in 1807. In August 1833 the British government passed the Slavery Abolition Act, advocated by William Wilberforce, which abolished slavery in the British Empire from August 1834, when some 800,000 people in the British empire became free. This monumental painting records the 1840 convention of the British and Foreign Anti-Slavery Society which was established to promote worldwide abolition. A frail and elderly Thomas Clarkson addresses a meeting of over 500 delegates.