The Battle of Chausa was fought between Sher Shah Suri and Humayun. After conquering Bengal , Humayun was headed towards Agra but Sher Khan had already blocked the way of return to the City. The Mughal  Emperor crossed the Ganges River  and reached Chausa but was met with Sher Shah Suri, who also reached there with his troops.The two armies remained there facing each other for two months. In this span of two months, the Mughal Army  suffered due to scarcity of Food and supply, which thus led to the death of horses and cattle. Now when the situation had become dire, Humayun was willing for negotiations and an arrangement for a treaty was made. As per this treaty, Sher Shah was to retain Bengal and parts of Bihar. In return, he would give recognition to emperor and accept his suzerainty.Sher Shah Suri was not pleased with the settlement and instead attacked the Mughals at night from all three sides. The Mughals were completely surprised and the army was destroyed. Humayun managed to escape and save his life by plunging himself into the Ganges River. And thus, Sher Shah won the Battle of Chausa and declared himself the Sultan.