The term armed merchant ship may describe a number of similar ship modifications intended for significantly different missions. The term armed merchantman is generally used. * East Indiaman describes late 18th and early 19th-century sailing ships engaged in trade while carrying guns similar to contemporary warships. * Defensively Equipped Merchant Ships were civilian-manned cargo ships carrying a small number of military personnel to operate an anti-submarine gun and anti-aircraft machine guns during the world wars of the early 20th century. * Auxiliary cruisers were cargo ships commissioned as naval vessels with a military crew, converted to carry the guns of a light cruiser, and sometimes used as Merchant raiders. * Armed merchant cruisers were fast passenger liners commissioned as n