 After a long campaign for abolition led by Thomas Clarkson and in the House of Commons by William Wilberforce, Parliament prohibited the practice by passing the Slave Trade Act 1807 which was enforced by the Royal Navy's West Africa Squadron.Britain used its influence to persuade other countries around the world to abolish the slave trade and sign treaties to allow the Royal Navy to interdict their ships.Somersett's case in 1772 held that slavery had no basis in English law and was thus a violation of Habeas Corpus.