The War of Jenkins' Ear (known as Guerra del Asiento in Spain), was a conflict between Great Britain and Spain that lasted from 1739 to 1748, with major operations largely ended by 1742. Its unusual name, coined by Thomas Carlyle in 1858, refers to an ear severed from Robert Jenkins, captain of a British merchant ship. The severed ear was subsequently exhibited before Parliament. The tale of the ear's separation from Jenkins, following the boarding of his vessel by Spanish coast guards in 1731, provided the impetus to war against the Spanish Empire, ostensibly to encourage the Spanish not to renege on the lucrative asiento contract (permission to sell slaves in Spanish America).