Westminster Abbey politicians, doctors and scientists such as Isaac Newton, buried on 4 April 1727, Charles Darwin, buried on 26 April 1882, and Stephen Hawking, buried on 15 June 2018. Another was William Wilberforce who led the movement to abolish slavery in the United Kingdom and the Plantations, buried on 3 August 1833. Wilberforce was buried in the north transept, close to his friend, the former Prime Minister, William Pitt. During the early 20th century it became increasingly common to bury cremated remains rather than coffins in the abbey. In 1905 the actor Sir Henry Irving was cremated and his ashes buried
Slavery notably France and the British colonies. Between 1808 and 1860, the British West Africa Squadron seized approximately 1,600 slave ships and freed 150,000 Africans who were aboard. Action was also taken against African leaders who refused to agree to British treaties to outlaw the trade, for example against "the usurping King of Lagos", deposed in 1851. Anti-slavery treaties were signed with over 50 African rulers. In 1839, the world's oldest international human rights organization, Anti-Slavery International, was formed in Britain by Joseph Sturge, which campaigned to outlaw slavery in other countries. There were celebrations in 2007 to commemorate the 200th