There was a perception that the company was trying to convert Hindus and Muslims to Christianity, which is often cited as one of the causes of the revolt. The revolt is considered by some historians as a semi-national and semi-religious war seeking independence from British rule though Saul David questions this interpretation. The revolt started, among the Indian "sepoys" of British East India Company, when the British introduced new rifle cartridges, rumoured to be greased with pig and cow fat—an abhorrent concept to Muslim and Hindu soldiers, respectively, for religious reasons. 150,000 Indians and 6,000 Britons were killed during the 1857 rebellion.