Ellis, William chief of the company's factory at Patna, was immediately responsible for the war between Nawab mir qasim and the east india company. William Ellis was one of those company officials who abused most grotesquely the dastak (pass) for company's trade free of inland duties. After the battle of palashi, the company officials felt dominant enough to conduct quite illegally their private trade free of inland duties. Consequent upon the abuse of the dastak by the European private traders, the native merchants were falling out of competition and thus they were losing country business to the company.
As a solution to the problem, Mir Qasim abolished inland duties altogether so that all could compete on the same footing. William Ellis looked at the measure as a hostile act and reacted by trying to capture Patna. Mir Qasim advanced his troops, defeated and killed him and seized the Patna Factory of the company. This local incident precipitated the full-scale war between the nawab and the company. Mir Qasim was finally defeated at the battle of buxar (1764), an event that led eventually to the establishment of British rule in Bengal. [Sirajul Islam]