The Barons of England were angry with the King and eventually rebelled against him because he over-taxed them for his unproductive wars in French territory and forced him to sign the Magna Carta which limited his power as King.
They eventually gained leverage because the English monarchy needed money to pay ransom for John's brother who was abducted and made prisoner by Emperor Henry VI and to fund the Crusades.
British disregard of religious beliefs and practices.
A rumour was spread that the riffles for cartridges were made from cow and pig fat. Cows are very sacred in Hindu customs, and are not eaten. Hindus reveres and worship cows. It is considered a sin to kill a cow and eat its meat.
