In short when Shēr Khān was apprized of the uprearing of the victorious standards, he left his son Qub Khān and many others in Cunār, and after strengthening the fort, departed to Bengal. He conquered that country in war and obtained much booty. When the world-conquering army of his Majesty Jahānbānī Jannat-āshiyānī encamped near Cunār, he applied himself to the taking of the fortress. Rūmī Khān who was the paragon of the age for overcoming grand forts and sky-high castles, and who had left Sulān Bahādur after the victory of Mandasōr, and been enrolled as one of his Majesty's servants, and exalted by the office of Mīr Ātash (Director of Ordnance) constructed a covered way (sābā) upon boats and arranged such a roof (saḥa) with strong partitions (?) on the top of a platform of planks that the ingenious and skilful bit the finger of astonishment in admiration of the workmanship.* And he carried such mines under the walls that when they were fired, Time and the Terrene (zamīn ū zamān) were shaken. Qub Khān fled, and the remainder of the garrison asked for quarter and came out. The fort fell into the possession of the king's servants. As for those admitted to quarter, they were about 2,000 in number, though his Majesty Jahānbānī had ratified Rūmī Khān's promise and had pardoned (?) them, yet Mu'ayyid Bēg Dūldai,* who was one of the confidential officers, added to the order that their hands should be cut off, and represented that this was the king's command; such was the usurpation* of authority that he displayed! His Majesty Jahānbānī censured him for this. Rūmī Khān received royal favours, and his influence and renown were increased. In return for his services the fort was made over to him, but in a few days he became by destiny an object of envy to the world and passed away, poisoned.
When his mind was free of this affair, the expedition to Bengal presented itself before him. Naṣīb Shāh,* the ruler of Bengal, came wounded to the world-protecting Court, and implored help against Shēr Khān. This was an additional reason for conquering Bengal, and another call to him to proceed there. His Majesty comforted him by his princely sympathy, and distinguished him by royal favours. As the expedition had now been determined upon, Jaunpūr and its territory was made over to Mīr Hindū Bēg who was one of the great officers, while Cunār was given to Mīrak Bēg. Preparations having been made, the army proceeded by land and water. When Patna became the camping ground, the loyal servants of the Court represented that the rainy season had arrived, and that if his Majesty delayed the Bengal expedition until this season had passed over, this would be consonant with the rules of conquest, since the passage of cavalry into Bengal at this season was very difficult, and would be productive of destruction to the soldiers. The ruler of Bengal looked to his own interests and represented that Shēr Khān had not yet confirmed himself in Bengal, and that to march speedily against him would be a means of extirpating him with ease. His Majesty out of consideration for this oppressed one, and from the plausibility of his statements, gave orders for the advance. In Bhāgalpūr he divided the army, sending M. Hindāl across the river with 5000 or 6000 men to march along its banks on that side. When the army had encamped at Monghyr, news came that Jalāl Khān, the son of Shēr Khān, who after his father's death took the name of Salīm Khān,* with Khawāṣṣ Khān, Barmazīd,* Sarmast Khān,* Haibat Khān Niyāzī,* and Bahār Khān* with about 15,000 men had come to Gaṛhī which is, as it were, the gate of Bengal, and that having strengthened it they were meditating strife and sedition.
The account of this affair is as follows: When Shēr Khān heard of the approach of the imperial army he could not bring himself to fight but went off by way of Jhārkhand,* so that when the grand army came into Bengal, he might go to Bihār and stir up commotion in that province, and also that he might place the spoils of Bengal in safety. He left Jalāl Khān and a large body of men near Gaṛhī and arranged that when the conquering army approached and he himself had got to Shērpūr,* they should make haste to join him, and should avoid fighting. His Majesty deputed from Bhāgalpūr Ibrāhīm Bēg Cābūq, Jahāngīr Qulī Bēg, Bairām Bēg, Nahāl Bēg, Rōshan Bēg, Gurg ‘Alī Bēg, Bacaka Bahādur, and a large force consisting of about 5000 or 6000 men. When the imperial army arrived in the neighbourhood of Gaṛhī, Jalāl Khān departed from his father's instructions, got together his army and attacked the camp. The men of it had not put themselves in order for fighting so as to combat properly. They were not properly drawn up, and the enemy was numerous. Nor were the former ready for battle. Bairām Khān turned several times and attacked the enemy, and dispersed them. He made gallant efforts but from want of management he was not properly supported, and things did not go satisfactorily. ‘Alī Khān Mahāwanī,* Ḥaidar Bakhshī and several other officers attained the glory of martyrdom. When this news came to the hearing of his Majesty, he rapidly proceeded to the spot. On the way the sea-adorning boat which was his special barge, was sunk at Colgong. When the royal army came near the black-fated Afghāns, the wretches fled. Mīrzā Hindāl, who had been appointed to Tirhut and Purnīyā was, at his own request, permitted to depart to his new fief, so that he should come from thence with a proper equipment to Bengal. His Majesty Jahānbānī proceeded from there, march by march, to Bengal, and by the Divine aid conquered it in 945.* Shēr Khān and the other Afghāns having taken the choicest treasures of Bengal* went off by Jhārkhand towards Rohtās, and got possession of it by means of stratagem.