Although he had no military training, Medwin was gazetted as a cornet in June 1812, joining his regiment at Cawnpore in Uttar Pradesh in northern India shortly thereafter. Cawnpore, far removed from the scene of the Gurkha or Nepal War of 1814–16, in which Medwin's regiment did not participate, was amongst the largest military stations in India, with an organised social life and stores stocked with European goods.