The Sur Empire (dë sru amparāturəi; emperâturi sur) was a Pashtun dynasty which ruled a large territory in the northern part of the Indian subcontinent for nearly 16 or 18 years, between 1538/1540 and 1556, with Sasaram (in modern-day Bihar) serving as its capital. The Sur dynasty held control of nearly all the Mughal Empire territories along the Indo-Gangetic Plain, from eastern Balochistan in the west of Indus River to modern-day Rakhine, Myanmar in the east. Sher Shah, an ethnic Afghan of the tribal house of Sur, first served as a private before rising to become a commander in the Mughal army under Babur and then the governor of Bihar. In 1537, when Babur's son Humayun was elsewhere on an expedition, Sher Shah overran the Sultanate of Bengal and established the Suri dynasty. The Sur supplanted the Mughal dynasty as rulers of North India during the reign of the relatively ineffectual second Mughal Humayun. Sher Shah defeated Badshah-i-Hind ('Hindustani emperor') Humayun in the Battle of Chausa (26 June 1539) and again in the Battle of Bilgram (17 May 1540). Sher Shah Suri was known for the destruction of some old cities while conquering parts of India. He has been accused by `Abd al-Qadir Bada'uni and other Muslim historians for destroying old cities in order to build new ones on their ruins after his own name. One example included Shergarh. Sher Shah is also said to have destroyed Dinpanah, which Humayun was constructing as the "sixth city of Delhi". The new city built by him, was itself destroyed in 1555 after Humayun re-conquered the territory from the Surs. Tarikh-i-Da'udi states, however, that he destroyed Siri. Abbas Sarwani states that he had the older city of Delhi destroyed. Tarikh-i-Khan Jahan states that Salim Shah Suri had built a wall around Humayun's imperial city. The Sur dynasty held control of nearly all the Mughal territories, from Balochistan in the west to modern-day Bangladesh in the east. Their rule came to an end by a defeat that led to the restoration of the Mughal Empire.