The battle of the Gogra River (4-6 May 1529) was the final major battle in the career of Babur, and saw him defeat Sultan Nasrat Ali of Bengal in a battle that was really only incidental to the main purpose of Babur's campaign in the east. Towards the end of 1528 Babur had dispatched part of his army, under his son Askari, to the east in an attempt to deal with some of the last Afghan opponents of his rule, most notably Biban and Shaikh Baiazid.
At first it had seems that Askari would be able to deal with any problems in the east, but this changed dramatically on 13 January when Babur received the news that Mahmud Lodi, a son of Sikander Lodi and at least a half brother of Ibrahim Lodi, the sultan of Delhi defeated by Babur at Panipat, had seized Bihar. Biban and Shaikh Baiazid had joined him, and it was clear that a major campaign would be needed. Babur had already mobilised his army, and so he was quickly able to move east.
The decision to move east was made on 21 January 1529. Babur reached the Ganges on 26 February, and two days later was joined by Askari, with his army. The two Mogul armies then advanced east, on opposite banks of the Ganges, heading towards Mahmud's force of 10,000 Afghans (including Sher Khan Sur, the man who would later depose Babur's son Humayun).
At first it looked as if the rebels would pose a major threat. They advanced west and besieged Chunar, but when news reached them of Babur's approach the rebel army broke up. Some of its leaders fled east while others, including Sher Khan, submitted to Babur. The problem now was that as Babur moved east he needed to enter territory that was claimed by Bengal. In mid April the army of Kharid, acting for Bengal, took up a position on the eastern bank of the Gogra, near the point where it flows into the Ganges, while the main army of Bengal was posted a little further east on the Gandak River. At this date the Ganges probably flowed further north than its current course, and the territory of Kharid may have reached down to the river, although Babur didn’t accept that claim.
The exact reason for the hostility between Babur and Nasrat Khan is unclear. Babur sent ambassadors who made three demands, but these are missing from Babur's memoirs. The Bengali answer to Babur's demands was clearly not adequate, and Babur began to plan his attack on the Gogra position, which now also contained Bengali troops.
The plan was arranged on 28 April. Babur's gunners were to be used to pin the Kharid and Bengali forces in place. Ustad 'Ali-quli was to advance to the point between the confluence of the Gogra and the Ganges, while Mustafa was to advance along the southern bank of the Ganges to a point just to the east of the confluence. They were then to bombard the enemy across the river to keep their attention while a large part of Babur's army, under Prince Askari, crossed to the north bank of the Ganges then advanced up the Gogra to the 'Haldi' passage, cross over and attack the Bengalis from the north-west. A second party was send another 16 miles up the river to investigate a second crossing point that could be used if the Bengalis fortified the Haldi crossing.
The battle itself is normally stated has having been fought on 4-6 May, although Babur's own memoirs place it one day early. Here we will follow the generally accepted date. On the morning of 2 May Babur's army crossed to the north bank of the Ganges, and Prince Askari's force began its march north-west up the Gogra. Two days later, on 4 May, the army advanced two miles downstream to the confluence, where the guns were set up and a harassing fire opened across the river.
On 5 May Babur dispatched a force of Mongols up the Gogra to find another possible crossing point. This movement was spotted from the far bank, and a force of Bengali foot soldiers crossed the river in 20 to 30 boats from a camp opposite Askari's camp. The Mongols charged the Bengalis, defeating them and capturing 7 or 8 boats. At about the same time the Bengalis crossed the Ganges to attack Babur's men on the south bank, but suffered another defeat. Three boats must have sunk on the way back across the river, and a fourth was captured.
The day also saw Prince Askari successfully cross the river, apparently somewhere to the north of the Bengali lines. Babur had decided to use the captured boats to send another force across the river in a different place, but when this news reached him this force was ordered to join Askari
On the morning of 5 May Askari advanced down the eastern bank of the Gogra, while the Bengali cavalry moved north to face him. Babur responded by ordered the men with him to cross the river, at first in captured boats. This small party was attacked by the Bengalis, but held them off. This success encouraged the rest of Babur's men to try and cross the river - some in boats, some swam and some used bundles of reeds - either as floats or as rafts.
At this point Babur's men were quite vulnerable, but he was able to organise them before the Bengalis could take advantage. Babur's men then attacked the southern flank of the Bengali force, just as the first of Prince Askari's men arrived from the north. The Bengalis were now being attacked from two sides, and this was enough to convince them to retreat east down the Ganges.
Babur doesn't mention any determined pursuit of the Bengali army, who after all were not the main target of his expedition. Over the next few days messengers arrived from Nasrat Shah, and peace was arranged.
Mahmud Lodi rather disappears from the picture at this point, but Biban and Baiazid were soon on the move, heading west. Babur set off in pursuit, but he was never able to catch them, and they were both still undefeated at the time of his death in 1530.