Khusro Khan, or Khusru or Khusraw Khan was a medieval Indian military leader, and ruler of Delhi, as Sultan Nasir-ud-din, for a short period of time.He was a Dalit (Parwari-Mahar) caste from Gujrat. He converted to Islam from Hinduism at the time of his capture. He was a untouchable in his own religion, but became a first SC to sit on the throne of Delhi.

http://en.wikipedia.org/wiki/Scheduled_castes_and_scheduled_tribes