In Bengal, the company wished to appoint a puppet Nawab, who was intelligent and clever, and who could fulfill their self – interests. Mir Qasim wished to check the power of the British from increasing any further and to prevent his own power from decreasing.

For this, he tried to reorganize the administration, but due to British interference, he could not succeed. Now, difference began to increase between both in context to financial matters and facilities, which resulted into the Battle of Buxar. Reasons of the Battle of Buxar.

1. The desire of sovereignty of the Nawab was not liked by the Britishers. Nawab’s tasks such as changing the capital from Murshidabad and taking it to Munger, training the army with European characteristics, opening ammunition manufacturing and cannon and explosive making factories etc. increased the difference between the British and the Nawab.

2. The Britishers forced the Nawab to present a gift of 12 lakh rupees to Mughal Emperor Shah Alam, which the nawab took as a blow to his independence.

3. The Company and its officials were misusing the trading facilities provided to them in Bengal. The Nawab was facing financial losses due to this. The Nawab granted this rebate to Indian traders also. Due to this, the British became unhappy with the Nawab.

4. The Nawab demanded to get back the three districts – Burdwan, Midnapur and Chatgaon which were obtained by the Company during the treaty of 1760, in the form of military expenses and the revenue collected from there, because the army was being used against the Nawab.

5. Struggle between Mir Qasim and the Britishers – When the efforts of compromise between the Calcutta Council and the Nawab failed, a battle started between both of them. In June 1763, Major Andemaz was sent to fight against Mir Qasim.

Several battles were fought with the armies of the Nawab, among which, the most famous battles were that of Katwaha, Gherian, Sooti and Udhwanala. When Mir Qasim’s side weakened, he went off to Patna. The Britishers reappointed Mir Zafar as the Nawab.

6. Formation of alliance – After getting defeated, Mir Qasim saved his life and reached Nawab Shuja-ud-Daula of Awadh for help. At that time, Mughal Emperor Shah Alam was also present in Awadh. All the three joined hands and made a plan of throwing the British out of Bengal.

This battle took place between the British and the joint armies of all the three (Mir Qasim the Nawab of Bengal, Shuja Ud Daula the Nawab of Awadh and Mughal Emperor Shah Alam) on 22nd October 1764. The British won this battle.