The Sultans of Delhi came from relatively humble origins. They were  slaves who rose to become generals in the armies of the Afghan ruler Muizz  al-Din Ghuri. Their transformation into rulers of a kingdom of great political  influence in North India was a slow and discontinuous process that occurred  through the thirteenth century. 
  For the better part of that century, there were many centres of  social and political power in the early Delhi Sultanate. There were military  commanders with contending political ambitions, as well as urban elites with  contrasting social constituencies, religious ideologies, and personal  commitments. Such people did not always support authoritarian interventions  seeking to create a monolithic state. 
  So, for decades, the Sultanate  seemed to disappear from political reckoning, and its resurrections were more  in the nature of reincarnations. It made its periodic reappearances in bodily  forms different from those of its precursors. Ultimately, the Delhi Sultanate  survived not just because of the political and military acumen of its rulers  and military agents, but because of the ideological investment of a variety of  Muslim émigrés that saw the Delhi Sultanate as a sanctuary for Muslims during  the period of Mongol holocaust. 
  In The Emergence of the Delhi Sultanate, Sunil Kumar charts the history of the structures that sustained and challenged  this regime, and of the underlying ideologies—eliding its sometimes ephemeral  form—that gave meaning to the idea of the Delhi Sultanate.