A regimental history traces four British cavalry units that carried the number nineteen, recounting their origins, reorganizations, and service across major 18th- and 19th-century campaigns. It follows early formation and deployments in Ireland and India, detailing actions in southern India including the Mysore wars, notable charges at battles such as Assaye and Argaum, and later service in North American operations during the War of 1812. The narrative continues with a unit raised during the Indian Mutiny and its later imperial campaigns in Egypt, Suakin and the Sudan, describing engagements, honors, organizational changes, and the social and institutional memory preserved in regimental records.