Delhi is called the city of cities as it was built over and over with different names and geographic extents and by various rulers for different purposes; fortification reasons, being closer to sources of water, or create a magnificent city as a display of power and wealth.
As a result, there are seven cities in Delhi which were the precursors to the Delhi we know today. The eighth city was built by the British as the New Delhi or the Lutyen’s Delhi which was designed by the imperial architect- Edward Lutyens as the centre of administration which has today came to be the centre of our democratic setup today housing the Parliament house, Rashtrapati Bhawan etc.
The seven cities are as follows – Siri, Tughlqabad, Jahanpanah, Firozobad, The city around Purana Qila, Shahjahanabad, New Delhi.
The first city of Delhi — Lal Kot/Qila Rai Pithaura — is situated in Mehrauli, whose name remains the same today and is on the Southern border of the modern city. There is documented evidence for the foundation of Delhi that the first Tomar king Raja Anangpal Tomar founded it in AD 736. Historians say probably chose the rocky Aravalli hills in Mehrauli as his headquarters for the military advantages it offered due to its terrain. It is said to be one of the reasons why Qutbuddin Aibak, the first Sultan of Delhi, who took over the region and some of his successors continued to live in the Lal Kot/Qila Rai Pithaura area for some years after he invaded the city. It was renamed Qila Rai Pithauria after ruler Raja Prithviraj Chauhan whose ancestors defeated the Tomars, and it was agreed that Tomar would marry a Chauhan princess and their offspring would rule over the city. That son was Prithviraj Chauhan
Lal Kot is said to be the first Red fort of Delhi. It lies in the present day, Sanjay Van. An Archaeological Survey of India report states the walls of the fort to be 28- 30 feet thick and 60 feet in height. Alexander Cunningham said there were ten gates to the fortress of which the Turks, who defeated the Chauhan ruler entered from the Ranjit Gate and renamed it to Ghazni gate. The remains of the gates can be seen today.