In the year 1772 the slave case Somerset v. Steuart was decided by the Court of King’s Bench. Somerset, an African slave purchased by his master in Virginia was set free by the authority of a high ranking English court. A well noticed landmark case, which should not alone question the institution of slavery, but contribute to British national identity and the legal structure of the Empire. The paper focuses on the judicial arguments of the litigating parties and the court, relating them to the contemporary public discourse on the legitimacy of slavery in Britain. Thus is revealed how and to what extent the judgment did contribute in its legal and discursive dimension to the abolition of slave trade and slavery that were to come.