Henry Hardinge introduced Enfield Rifles with greased cartridge in Indian army, which caused the revolution of 1857. Explanation & Key Takeaways: • Henry Hardinge, who was governor-general of India from 1844 to 1848, attempted to modernize the army's equipment as governor-general. • He introduced Enfield Rifles with greased cartridge in Indian army. • The introduction of new Enfield Riffles in the army became the immediate cause of the revolution of 1857. • The top of the cartridge of this rifle was to be removed by the mouth before loading it in the rifle. • The cartridges were greased by the fat of pig and the cow. • The Indian sepoys believed that the British were deliberately attempting to spoil the religion of both the Hindus and the Muslims because while the Hindus revered the cow, the Muslims hated the pig. • The soldiers, therefore, determined to refuse their service and, ultimately revolted. • Thus, the primary and the immediate cause of the revolt was the use of the greased cartridges. Hence, the correct answer is - Henry Hardinge.