After the Battle of Buxar, 1764, which was fought in Buxar, hardly 115 km from Patna, the Mughals as well as the Nawabs of Bengal lost effective control over the territories then constituting the province of Bengal, which currently comprises Bangladesh and the Indian states of West Bengal, Bihar, Jharkhand, Odisha. The British East India Company was accorded the diwani rights, that is, the right to administer the collection and management of revenues of the province of Bengal, and parts of Oudh, currently comprising a large part of Uttar Pradesh. The diwani rights were legally granted by Shah Alam, who was then the sovereign Mughal emperor of India. During the rule of the British East India Company in Bihar, Patna emerged as one of the most important commercial and trading centres of eastern India, preceded only by Kolkata.