Answer:
Meerut, the first area to receive the new weapons, was the epicenter of the sepoys' insurrection. British manufacturers quickly modified the cartridges in an attempt to quell growing military rage, but the action backfired. The switch merely confirmed in the sepoys' perceptions that the original cartridges had been smeared with cow and pig fat.
Unrest's Causes as the Indian uprising gained momentum, people discovered new reasons to oppose British rule. Princely families joined the rebellion in response to changes in inheritance law that made adopted children ineligible to succeed to the throne. This was an attempt by the British to exert influence over royal succession in nominally sovereign princely nations.