Political Causes: Lord Dalhousie's Doctrine of Lapse (Satara, 1848; Nagpur, Jhansi, 1854) and Lord Wellesley's Subsidiary Alliance systematically dismantled native sovereignty, alienating princely houses and creating widespread political insecurity.
Economic Exploitation: Ruin of traditional handicrafts by discriminatory British tariff policies, heavy land revenue settlements (Zamindari, Ryotwari, Mahalwari), and the transformation of India into an exporter of raw materials and importer of British finished goods.
Socio-Religious Fears: Rapid Westernization, interference in traditional customs (Abolition of Sati 1829, Widow Remarriage Act 1856), introduction of railways and telegraphs seen as sorcery, and activities of Christian missionaries creating fear of forced religious conversion.
Military Grievances: Racial discrimination in pay and promotion, General Service Enlistment Act (1856) requiring overseas deployment violating caste taboos, and the reduction of Indian soldiers' allowances (Bhatta).
Immediate Trigger: Introduction of the Enfield Rifle and the rumor that its greased cartridges were coated with animal fat (beef and pork), directly outraging the religious sentiments of both Hindu and Muslim sepoys.