 The question of a slave's rights as against his putative master (as opposed to merchant's rights as against each other) eventually came before Lord Mansfield and the King's Bench in 1771.A writ of "habeas corpus" had been issued to secure the release of James Somersett, a black man confined in irons on board a ship arrived in the Thames from Virginia, bound for Jamaica, and the return stated that he was a slave under the law of Virginia.Lord Mansfield was anxious to avoid the issue principle, and pressed the parties to settle; but the case was taken up by the West India merchants, who wanted to know whether slaves were a safe investment, and by abolitionists such as Granville Sharp, so that it became a "cause célèbre".