Bakhtiyar Khilji
Ikhtiyār al-Dīn Muḥammad Bakhtiyār Khaljī also known as Malik Ghazi Ikhtiyar 'l-Din Muhammad Bakhtiyar Khalji or Muhammad Bakhtiyar Khalji or simply Bakhtiyar Khalji : ), 
He was a military general of Qutb al-Din Aibak, who became the first Muslim to conquer Bengal. He was believed to be destroyer. With his invasions many monastries and viharas damaged or destroyed completely. Some of the famous architectures or Buddhist establishments were at Nalanda, Odantapuri, and Vikramashila. His invasion of Bengal ushered an era, lasting over five centuries, during which most of Bengal was dominated by rulers professing the Islamic faith. He established a town, which later became famous as BAKHTIYARPUR. He died in Bihar. You can visit his mausoleun at Biharsarif.                                                                                                                                                                SUR Dynasty
     During medieval period one of the most important dynasty ruled Bihar called SUR DYNASTY. This was during the time of SHER SHAH SURI. In the Battle of Chausa, Sher Shah defeated Humayun. Battle of Chausa took place in 1539 A.D. After Battle of Chausa, Sher Shah took the title of Sultan- e- Adil. He was very efficient administrator. He constructed the very famous Grand Trunk Road. He was financially skillfull. The revenue model by Sher Shah was also adopted by Akbar. Akbar is known for annexing Bihar and Bengal.