- Built by Qutb-ud-Din Aibak in Qila Rai Pithora, the ancient Hindu citadel.
- Built on the plinth of a Hindu temple which was dismantled.
- The plinth was expanded to cover a rectangle of 150' X 212'.
- This stylobate was then enclosed by a wall with cloisters on all sides.
- Cloisters were three aisles deep.
- Composed of pillars from Hindu temples, placed one above the other to achieve the desired height
- The western part of the cloister was the sanctuary.
- The arrangement of the pillars was made more spacious and resolved into a series of bays with shallow domed roofs.
- The courtyard is 105' X 141', surrounded by cloisters.
- In the front of the centre of the sanctuary stands the iron pillar with the Garuda motif removed from its pinnacle.
- In 1199, a screen of an arched facade was added across the front of the sanctuary.
- The screen is a wall of masonry 50' high at the centre, 108' wide and 81/2' thick.
- The screen is pierced by 5 arches, the central arch 45' high and 22' in span and two smaller ones on each side, each 25' high.
- Each smaller arch had a clerestory above it, mainly for decorative purposes as it did not serve in any way the sanctuary behind it.
- The facade is embroidered with carvings of floral devices and Quranic verses.
- The arches are not true arches but built by corbelling, hence we know they were built by local workmen acting on verbal instructions from a Muslim clerk of works.
- The ogee shape of the arch may be derived from the Buddhist caves of the Barahar hills of Bihar and the Stupas of Sarnath.