The Cambridge History of India, Vol. IV: The Mughul Period v4.c13.31

v4.c13.31

Gaur is about 350 miles east of Benares which was the nearest place really within the Mughul occupation. To secure communications and supplies Humāyūn left his brother Hindāl on the north bank of the Ganges, neglecting all precaution on the south, where the level alluvial plain soon meets the Kaimur range and its eastern extension. In these hills covered with thorny jungle and hence known as Jhārkhand, Sher Khān found a convenient base from which to develop his plan of cutting off Humāyūn from his capital. Hindāl soon deserted his post in north Bihār and there were grounds for suspecting his loyalty, while Sher Khān rapidly overran the south as far as the river, and crossing it took Benares. He sent his son Jalāl Khān to besiege Jaunpur, arrested and imprisoned the families of the leading men in the district, and invested Chunār. Though the governor of Jaunpur still held the city, reinforcements which arrived from Oudh were roughly handled by Jalāl Khān owing to the rashness of their leader.