Medieval history of Bihar is dealing with the glorious rule of Sher Shah Suri and Mughal Rule. The glorious history of Bihar lasted till around the middle of the 7th or 8th century A.D. until the Gupta Period. With the conquest of almost all of northern India by invaders from the middle-east, the Gupta dynasty gradually declined.

Muslim Rule in Bihar
During the medieval period Bihar lost its prestige as the political and cultural centre of India. During the Turko-Afghan period, Bihar formed a part of the Delhi Sultanate. The emergence of Delhi Sultanate, for the first time, marked the development of an autonomous Muslim power in India. The Delhi Sultanate reined India from 1290 to 1526 AD. Till this time, Delhi has served just as a base for the Muslim powers to rule while, in truest sense, Lahore remained the capital. The Slave dynasty, undoubtedly, made Delhi their capital but it was the rulers of Delhi Sultanate that strengthened the base. The first ruling empire that was part of the Delhi Sultanate was the Khilji Dynasty. Later it was ruled by the mighty rulers of Slave Dynasty, Tughluq Dynasty and the Delhi Sultanate. Powerful rulers like Ikhtiyaruddin Muhammad bin Bakhtiyar, Qutub- Ud- Din Aibak, Illtutmish, Firoz Shah Tughlaq, Ghiyas- ud- din Tughlaq, Sikandar Lodi and Ibrahim Lodi have ruled the state during the medieval period.

Mughal Rule in Bihar
The Mughal Period was a period of unremarkable provincial administration from Delhi. The only notable person during that time was Sher Shah Suri an Afghan. Based at Sasaram which is now a town in the district of the same name in central-western Bihar, this jagirdar of the Mughal King, Babur was successful in defeating Humayun, the son of Babur, twice once at Chausa (Battle of Chausa)and then, again, at Kannauj that is currently located in the in the present state of Uttar Pradesh. Through his conquest Sher Shah became the ruler of a territory that, again, extended all the way to the Punjab. He was noted as a ferocious warrior but also a noble administrator. However during the medieval period, Bihar saw period of glory for about six years during the rule of Sher Shah Suri. He was instrumental in building the Grand Trunk Road, the longest road of the Indian subcontinent that stretches from Kolkata and ends at Peshawar, Pakistan. Many economic reforms were carried out by Sher Shah, like the introduction of Rupee and Custom Duties. He revived the city of Patna; where he built up his headquarter.

From 1557 to 1576, Akbar the Great, the Mughal emperor, annexed Bihar and Bengal to his empire. However with the downfall of the Mughals, Bihar passed under the control of Nawabs of Bengal. This period saw exploitation at the hands of the rulers in the form of high taxes, but the Nawabs of Bengal also allowed trade to flourish in this region.