Prelude
Following the seizure of Patna's government, Shamshir Khan encamped in Mir Jafar Khan's garden outside the city, appointing Murad Sher Khan as its administrator. Predicting counter-attack by Alivardi Khan, Shamshir Khan rapidly expanded his forces through intensive recruitment of Afghan soldiers. He summoned Afghan tribal kinsmen from various regions to rally under his banner. [8] Within three months 40,000 cavalry and almost same number of infantry was recruited. [5] The infantry also consisted musketeers under Bahelia command. [9] They also had a strong artillery sieged from Patna. [10]
Additionally, the Marathas, requested by the Afghans proceed to Patna and joined the Afghan forces in a planned assault on Alivardi Khan. The Maratha contingents, led by Mir Habib and Janoji, subsequently reinforced the Afghan army. [11]
Alivardi's arrangements and advance
On 30 January, Alivardi was informed the assassination of his nephew Zain ud-Din, death of his brother Haji Ahmad and the disgraceful treatment of his daughter Amina Begum. He resolved to recapture Patna, liberate his surviving relatives held captive by the Afghans, and avenge the deaths of his two close kinsmen. [12] After arranging the necessary precautions Alivardi left Amaniganj on 29 February and reached Bhagalpur on 16 March 1748 with 15,000 or 16,000 cavalry and 20,000 infantry. [2] At Bhagalpur, Mir Habib's Marathas, pursuing Alivardi from Bengal via a shorter jungle path, emerged near Champanagar and attacked the Nawab's rear. The Marathas were defeated and routed. [13] They then advanced to Munger. Saif Khan of Purneah dispatched Shaikh Din Muhammad with 1,500 soldiers near Sultanganj. [14] Marching from Sultanganj, Alivardi Khan halted at Monghyr for several days. [15] There, he was reinforced by Raja Sundar Singh of Tikari, who arrived with 1,500 cavalry and a contingent of infantry, as well as by Kamgar Khan Mayi, the zamindar of Narhat and Samai. The Bengal army advanced from Munger and soon reached Barh. [16]
Battle
At Barh the Afghans received the information that Mir Habib and Janoji had reached Patna. Shamshir Khan and Sardar Khan received the Maratha army in their camp near Patna. [17] The next day detained Mir Habib, Mirza Mahmed Saleh, Mohan Singh, and other Maratha officers, demanding 30–40 lakhs of rupees as payment, claiming the Marathas had incited the rebellion and promised to cover costs. The officers were released after Mir Habib provided security for two lakhs. [18] Shamshir Khan leaving Ahmad Khan Qureshi with 2,500 soldiers in charge of Patna, advanced towards Barh with Maratha army to counter Alivardi Khan who was coming towards Patna. [19]
The Afghan forces numbered approximately 35,000, while the Marathas were at 12,000. [4] Alivardi Khan's army consisted of an estimated 15,000 cavalry and 8,000 foot musketeers. [3]
They encamped with guns on the opposite side of the river. Alivardi Khan, guided by a local zamindar, crossed the narrow southern branch of the Ganges at an unknown ford south of Barh. Upon this maneuver, the Afghans abandoned their entrenched position with its heavy guns and fled westward to Alivardi's new position. Alivardi's forces had to crossed the river at night with great caution. [20]
On the morning of 16 April 1748, Alivardi Khan advanced to the village of Rani Sarai [b] and arrayed his forces on the adjacent plain. Bahadur Ali Khan commanded the vanguard with the Nawab's heavy artillery positioned at the front. Behind them were the lighter guns under Haider Ali Khan, Rahmat Khan, Mir Kazim Khan, and Dost Muhammad Khan. The cavalry and infantry of the advance guard followed, led by Sayyid Ahmad Khan, Allah Yar Khan, Mirza Iraj Khan, Raja Sundar Singh, and Kamgar Khan Mayi. Alivardi positioned himself at the center, flanked closely by Umar Khan and his four sons—Asalat Khan, Diler Khan, Ahmad Khan, and Muhammad Khan. The Afghan main force deployed opposite the Bengal army in a line extending nearly three miles eastward from Rani Sarai, with the allied Marathas positioned at an angle facing the Nawab's left wing. The Afghan left wing, under Hayat Khan and equipped with heavy guns, crossed a narrow stream to the Ganges to target the Bengal right wing upon its approach. [21]
At the beginning of the clashes a cannon fire blew Sardar Khan's head who was at the command of half of Afghan troops. [22] Haider Ali Khan immediately led his musketeers in an assault, firing repeated volleys that obscured the daylight with dense smoke. As the Afghans fell into disarray, Alivardi Khan ordered Shah Jahan Yar and Fakhrullah Beg Khan to charge, but they remained stationary. Meanwhile, the Marathas under Mir Habib, seeking to divert attention in support of their allies, attacked Alivardi's baggage train in the rear and advanced toward the center. Siraj ud-Daula, positioned near his grandfather, became alarmed and urged the Nawab to repel them at once. Disregarding this plea, Alivardi directed his vanguard to charge the Afghans head-on and advanced personally behind it. Several of his generals, mounted on elephants, plunged boldly into the enemy ranks. Struck by a musket ball, Murad Sher Khan collapsed into his elephant, whereupon two of the Nawab's generals, Mir Kazim Khan and Dost Muhammad Khan, attacked him. Despite his wounds, Murad Sher Khan severed several fingers of Mir Kazim Khan, but Dost Muhammad Khan promptly decapitated him. Simultaneously, Shamshir Khan was wounded and fell from his elephant; Mirza Habib Beg a retainer of the Nawab's general Diler Khan immediately beheaded him. Devastated by the loss of their commanders, the Afghans fled the field, while their Maratha allies, who had played no significant role in the day's combat, likewise withdrew. [23]
Bengal Subah 
