Aurangzeb remained a remarkably vigorous ruler for a half century (1658–1707) before he died at age ninety. During the first twenty years of his reign the emperor kept his capital at Shahjahanabad Delhi. In the next decade the grand encampment became the movable capital of the empire as the emperor campaigned actively in Rajasthan and the Deccan. Throughout the first thirty years of his reign Aurangzeb, who had added “Alamgir” or “world-seizer” to his titles, dedicated himself to fostering a more properly Islamic regime and to aggressive expansion on the empire's frontiers. However, several unrewarding campaigns in the 1660s and 1670s beyond the mountain rim of the subcontinent graphically revealed the harsh costs to further expansion in the north. These campaigns reinforced the emperor's pronounced inclination to move south – to conquer lands long accustomed to Islamic rule.

TESTING THE LIMITS OF EMPIRE: NORTHEAST

To the northeast, Bengal's growing export economy and Muslim settler frontier seemed a likely area for aggressive campaigning. Imperial authority still rested lightly in this region. When Prince Shuja's governorship of Bengal was interrupted by the succession war, zamindars like Prem Narayan, the ruler of Kuch Bihar, rebelled. Simultaneously, Jayadhwaj Sinha, the Ahom king, sent an army to invade and annex Kamrup, the Mughal border district on the Brahmaputra river.

In mid 1660, Aurangzeb, determined to regain control of the northeast, appointed Muhammad Said Mir Jumla, his collaborator in the Deccan, to be governor of Bengal, Bihar, and Orissa.