Letter

Letter of Marque, an extraordinary commission by the Lords of the Admiralty or the vice-admiral of a distant province to a commander of a merchant-ship or privateer to cruise against and make prize of an enemy's vessels by way of reparation for damage inflicted by that enemy. Ere such a letter could be granted it was necessary to make oath concerning the damage sustained, to offer proof that legal prosecution had been ineffectual, and to petition the head of the State for justice. Another name for the same commission is Letter of Reprisal. The Treaty of Paris (1856) formally abolished all such commissions, but the United States, Spain, and Mexico never adhered to the understanding, which, no doubt, would be disregarded in war time by any Power which might find the treaty opposed to its apparent interests.