The "Battle of Chausa" was fought between the Mughal emperor, Humayun, and the Afghan emperor Sher Shah Suri.
It was fought on 26 June 1539 at Chausa, located in the southwest of Buxar, now in Bihar.
In this battle, Sher Shah defeated Humayun and crowned himself as Farid al-Din Sher Shah.
The Mughal emperor Humayun again faced Sher Shah in the Battle of Kanauj and was again defeated by him.