Hostilities officially began on June 25th, 1763 when Company agent William Ellis, initially sent to as part of a delegation to mediate negotiations with the Nawab Mir Qasim , attacked his capital city of
Patna with a force of some 300 British infantrymen and 2,500 sepoys and was met with a counterattack of some 10,000 Sepoys and rebels loyal to Mir Qasim led by his
Armenian mercenary general Gurgin Khan soon after, leading to a British defeat and the capture of Ellis. After the defeat of British forces at the battle, command was put under the command of
Major Thomas Adams who began the campaign on July 2nd, the first major engagement of the campaign was at
Katwa. At the onset, Qasim had numerical superiority and superior artillery, led by Gurgin Khan, though it was fraught with internal strife and the column that engaged Liuetenant Glenn's force near the British camp of Agradwip on the morning of the 17th was considerably smaller and led by a band of cavalry irregulars, who after hours of fighting were defeated by the British who continued to press towards the fort at Katwa, which surrendered with feeble resistance. Then, on the 19th of July, Mir Qasim's general, the Faujdar of
Birbhum Mohammed Taki Shah moved the vanguard of his force to Takwa which saw "one of the bloodiest and best-contested battles of the whole war." Ultimately Taki Shah was killed and Qasim was forced to retreat Mir Qasim set up his defenses near
Jangipur on
Sooty on the plain of
Giria. British forces under Major Thomas Adams attacked on 2 August 1763 and, after a bloody battle, forced Mir Quasim to retreat to Udaynala. Mir Qasim was defeated again at Udaynala, where the British headed by Major Thomas Adams successfully stormed a well-defended
Ganges gorge at
Teliagarhi downstream of
Rajmahal on 5 September 1763. After inflicting heavy losses at the gorge, Adams captured
Monghyr. After Udaynala, Mir Qasim killed the British soldiers captured in the 1st battle of Patna. Major Thomas Adams besieged Patna and captured the town in the 2nd battle of Patna on 6 November 1763 that saw heavy losses in the Bengal army.
Mir Qasim forged an alliance against the East India Company with Mughal Emperor
Shah Alam II and the
Awadhi Nawab Shuja-ud-Daula. On 3 May 1764 British EIC forces under the command of Colonel John Carnac were victorious in a 3rd battle at Patna against the Nawab of Oudh Shuja-ud-Daula. The British occupied defensive positions outside of Patna and caused heavy losses for the attacking Shuja's forces. After repulsing the attack, Carnac decided against a pursuit, but heavy rains caused Nawab's retreat a month later.
Battle of Buxar On 23 October 1764, following the 3rd Patna battle, British forces under the command of
Major Hector Munro, despite their numeric inferiority, carried a decisive victory over Indian allies at
Buxar, west of Patna. After the battle of Buxar, Mir Qasim's and Shujah-ud-Daula's forces retreated into
Gangetic Doab with Major
John Carnac in pursuit. They managed to join forces with a
Marathi army headed by
Malhar Rao Holkar. On May 1765 the British successfully defeated them. After the rout that followed, Malhar Rao fled to
Kalpi, and Mir Qasim sued for peace. ==Aftermath==