[6] The origins of the Purana Qila lie in the walls of Dinpanah, the new city of Delhi was being constructed by Mughal emperor Humayun, in the general vicinity of the ancient Indraprastha ruins.

[8] The founder of the Sur Empire, Sher Shah Suri, defeated Humayun and made changes to the fort, strengthening its fortifications and completing its walls.

Tarikh-i-Da'udi states that Sher Shah Suri's royal city remained incomplete upon his death and he had named his fort Shergarh.

On 7 October 1556 Hindu king Hem Chandra Vikramaditya, who had defeated Akbar's forces at Battle of Delhi (1556) was crowned in Purana Qila.

[citation needed] Edwin Lutyens who designed the new capital of British India, New Delhi, in the 1920s, had aligned the central vista, now Rajpath, with Purana Qila.

[10] During the Partition of India, in August 1947 the Purana Qila along with the neighbouring Humayun's Tomb, became the site for refuge camps for Muslims migrating to newly founded Pakistan.

[13] The fate of the Japanese in India threw a shadow over the whole business, and the British believed, with some justification, that the ill-treatment of Allied prisoners of war was a reprisal for this.

( R. N. Gilchrist to under secretary of state, Foreign Office, 19 October 1942, ibid) In the 1970s, the ramparts of Purana Qila were first used as a backdrop for theatre, when three productions of the National School of Drama were staged here: Tughlaq, Andha Yug and Sultan Razia, directed by Ebrahim Alkazi.

This includes Painted Grey Ware, dating 1000 BC, and various objects and pottery signifying continuous habitation from Mauryan to Shunga, Kushana, Gupta, Rajput, Delhi Sultanate and Mughal periods.

All the gates are double-storeyed sandstone structures flanked by two huge semi-circular bastion towers, decorated with white and coloured-marble inlays and blue tiles.

Marble in shades of red, white and slate is used for the calligraphic inscriptions on the central iwan, marks a transition from Lodhi to Mughal architecture.

This double-storeyed octagonal tower of red sandstone with steep stairs leading up to the roof was intended to be higher than its existing height.

Its original builder was Babur who ordered the construction and was used as a personal observatory and library for his son Humayun, finished only after he recaptured the fort.

[clarification needed] The tower is topped by an octagonal chhatri supported by eight pillars and decorated with white marble in typical Mughal style.

[citation needed] Several other monuments are strewn around the complex, like Kairul Manzil, mosque built by Maham Anga, Akbar's foster-mother, and which was later used as a madarsa.