This Mosque was built by Aurangzeb (Aurangzeb or Alamgir, Conqueror of the Universe) was the third son of Emperor Shah Jahan.
He did not follow his father's liberal views. He was known as a fundamentalist Muslim, original Taliban).
It was built on the site of an Hindu temple which was destroyed at the time of the Mughal invasion.
He decided to build this Mosque there in order to dominate the skyline of the whole city.