The major cause of the Sepoy Mutiny in India in 1857 stemmed from various grievances held by Indian soldiers (sepoys) in the British East India Company's army. Key factors included the introduction of the Enfield rifle, which required soldiers to bite cartridges greased with animal fat, violating religious beliefs. The resentments towards British policies, economic exploitation, and cultural insensitivity fueled widespread discontent among Indian soldiers and civilians alike. The uprising, also known as the First War of Independence, marked a significant turning point in British colonial rule and led to increased awareness of national identity and resistance in India.