 The case has since been misrepresented as finding that slavery was unlawful in England (although not elsewhere in the British Empire).A similar case, that of Joseph Knight, took place in Scotland five years later and ruled slavery to be contrary to the law of Scotland.Following the work of campaigners in the United Kingdom, such as William Wilberforce and Thomas Clarkson, the Act for the Abolition of the Slave Trade was passed by Parliament on 25 March 1807, coming into effect the following year.