In 1857 the Indian troops of the Bengal Army rose against their colonial masters. They were quickly joined by tens of thousands of discontented civilians in what was to become the bloodiest insurrection in the history of the British Empire. For much of the last century, Indian and British scholars downplayed the importance of professional grievances in their accounts of why the military insurrection of 1857 took place. Most viewed the Bengal sepoys as uniformed peasants who were affected by the same social, economic and religious concerns as their civilian counterparts. They tended to identify the defence of caste and religion as the key to the military uprising, while regarding the latter as little more than a precursor to a general revolt. Yet this study's identification of professional concerns as the essential cause of the Indian Mutiny is very much in line with the recent historiography of military revolts. All armies have grievances relating to conditions of service, particularly pay, career prospects and relations with officers. What set a colonial force like the Bengal Army apart is that it was a volunteer mercenary force officered by men of a different race and religion. Its loyalty to its paymasters, therefore, was entirely dependent on the incentives for service outweighing the disincentives. David argues that by 1857 this was no longer the case: primarily because the number and seriousness of the sepoys' grievances was increasing, while the Bengal Army's control over its soldiers was weakening.