Prithviraj Chauhan built Qila Rai Pithora in the 12th century as the capital, extending the original fort city of Lal Kot built by the Tomar Rajputs. The ruins of Qila Rai Pithora's ramparts can still be seen near Qutub Minar and Mehrauli. Alauddin Khilji of the Khilji dynasty established the fort city of Siri and had the Hauz Khas madrasa constructed, showing West Asian influences. In 1330, Ghias-ud-din Tughlaq founded the Tughlaq dynasty and built the fortified city of Tughlakabad to defend against Mongol invaders