India remained a patchwork of states, many of them nominally independant but actually under strong British influences. In 1857, less than a half century after Britain had taken firm control of India, they had their first serious setback. The dismissal of local rulers, inefficient and unpopular as they might have been, proved to be a flashpoint in certain areas, but the main single cause, believe it or not, was bullets. A rumour, quite possibly true, leaked out that a new type of bullet issued to the troops, many of whom were Muslim, was greased in pig fat. A similar rumour was developed that the bullets were actually greased with cow fat.
Pigs are unclean to the muslims and cows holy to the hindus.
The British were slow to deny these rumours and even slower to prove that they were either incorrect or that changes had been made. The result was a loosely coordinated mutiny of the Indian battalions of the Bengal Army. Of the 74 battalions, seven remained loyal, twenty were disarmed and the other forty seven mutinied. There were massacres and acts of senseless cruelty on both sides but in the end the mutiny died out. By the end of the century opposition to British rule began to take on a new light.