What was the consequence of Humayun War with Sher Khan?

After the loss of Gujarat in 1536, Humayun stayed in Agra for a year. Although he got information that Sher Khan was strengthening his position in Bengal and Bihar, he did nothing to move against him. Sher Khan had already made himself the master of the whole of Bihar. He had also defeated the King of Bengal in 1534 and 1536. It was only in 1537 that Humayun felt that he should do something against Sher Khan.

He besieged the fort of Chunar which belonged to Sher Khan. The siege lasted for 6 months and in spite of the best efforts of Humayun, it could not be captured. Ultimately, it was captured by means of a trick. The capture of the Fort of Chunar was a great military achievement, but it was of no substantial use to Humayun as this fort did not command any land-route. Humayun had wasted many valuable months in Chunar for nothing.

After capturing Chunar, Humayun proceeded towards Banaras and stayed there for some time. Negotiations were opened with Sher Khan for compromise. Instead of taking action against Sher Khan at once, Humayun waivered and ultimately decided to conquer Bengal. He reached Teliagarhi in May, 1538 and found the road to Gaur blocked by Jalal Khan, son of Sher Khan. There was fighting and Jalal Khan retired.

In August 1538, Humayun reached Gaur. Here again Humayun wasted about 8 months in merry-making. He neglected fighting during this period. During this interval, Sher Khan strengthened his position and cut off the communications between Delhi and Bengal. He also captured Kara, Kanauj and Sambhal.

By January 1539, the whole of the country between the Kosi and the Ganga was in the hands of Sher Khan. Hindal left Bihar and retired to Agra. When Humayun realised the dangerous position in which he was placed, he decided to return to Agra immediately. He started his return journey in March, 1539.