Purana Qila is not only the oldest fort among all forts in Delhi, but the oldest known structure of any type in Delhi. Located at the site of legendary city of Indraprastha, the fort was founded by Pandavas on the banks of perineal river Yamuna, which is revered by Hindus since ages. Fort is more than 5000 years old, and was constructed before the 'Mahabharata' took place.
Consequently the fort is considered to be 'the first city of Delhi'. Researchers now confirm that uptill 1913, a village called Indrapat existed with in the fort walls. Excavations carried out by Archaeological Survey of India
(ASI) at Purana Quila in 1954-55 (trial trenches) and again 1969 to 1973 by its Director, B B Lal have unearthed Painted Grey Ware dating 1000 B.C., confirming the antiquity of the fort.
Fort in Medieval Period:
Fort was called as the inner citadel of the city of Dina-panah during Humayun's rule who renovated it in 1533 and completed five years later. Purana Qila and its environs flourished as the "sixth city of Delhi".The founder of the Suri Dynasty, Sher Shah Suri, defeated Humayun in 1540, renaming the fort Shergarh; he added several more structures in the complex during his five year reign until his death in 1545.
Subsequently Islam Shah took over the reins of North India from this fort, but shifted his capital to Gwalior, as it was supposed to be a safer capital in that period, leaving the charge of Delhi and Punjab to his Hindu General Hemu. After Islam Shah's death in 1553, Adil Shah Suri took charge of North India. General Hemu was busy in quelling rebellion in east India and the fort remained neglected. Adil Shah shifted his capital further east to Chunar in present day Uttar Pradesh. Humayun, who was based in Kabul at this time, seized the opportunity to re-capture the citadel and the seat of Delhi in 1555, fifteen years after abandoning it following his defeats at the hands of the Suri Dynasty in the Battles of Chausa and Kannauj. Humayun's reign proved brief thereafter; he died following a tragic accidental fall within the fort complex at Sher Mandal only a year later, in Jan. 1556.
Hearing about re-capture of Delhi by Humayun, Hemu, the Hindu Prime Minister – cum – Chief of Army of Adil Shah, rushed towards Delhi from Bengal, where he had just quelled a rebellion, defeating and killing Muhhamad Shah, the ruler of Bengal. After capturing Agra, Itawah, and Kanpur with relative ease, Hemu, who had won 22 battles spanning entire north India, met and defeated the forces of Akbar, which were led by Tardi Beg Khan, in the Battle for Delhi, which took place in the Tuglaqabad area on 5–6 October 1556.
Hemu had his Rajyabhishek or Coronation at Purana Quila on 7 October 1556, declared 'Hindu Raj' in North India, and was bestowed the title of Samrat Hem Chandra Vikramaditya. Hemu, who later lost his life at the Second battle of Panipat in Nov. 1556, subsequently had his torso hung outside this fort to create terror among Hindus.
Delhi is thought to be located at the site of the legendary city of Indraprastha founded by the Pandavas from Mahabharata period, which is consequently considered the 'First City of Delhi', In support of this, until 1913, a village called Indrapat existed within the fort walls.
Archaeological Survey of India (ASI) carried out excavations at Purana Qila in 1954–55 and again from 1969 to 1973 by B. B. Lal, and its findings and artefacts are exhibited at the Archaeological Museum, Purana Qila. This includes Painted Grey Ware, dating 1000 BC, and various objects and pottery signifying continuous habitation from Mauryan to Sunga, Kushana, Gupta, Rajput, Delhi Sultanate and Mughal periods.
The single-domed Qila-i-Kuna Mosque, built by Sher Shah in 1541 is an excellent example of a pre-Mughal design, and an early example of the extensive use of the pointed arch in the region as seen in its five doorways with the 'true' horseshoe-shaped arches. It was designed as a Jami Mosque, or Friday mosque for the Sultan and his courtiers. The prayer hall inside, the single-aisled mosque, measures 51.20m by 14.90m and has five elegant arched prayer niches or mihrabs set in its western wall. 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. At one time, the courtyard had a shallow tank, with a fountain.
A second storey, accessed through staircases from the prayer hall, with a narrow passage running along the rectangular hall, provided space for female courtiers to pray, while the arched doorway on the left wall, framed by ornate jharokas, was reserved for members of the royal family. On a marble slab within mosque an inscription thus read, "As long as there are people on the earth, may this edifice be frequented and people be happy and cheerful in it". Today it is the best preserved building the Purana Qila.
The Sher Mandal named so after Farid (sher shah) who had tried to finish what was orderd by Babur but had died during the initial phase and so construcion was halted until the arival of Humayun.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 orderd the construction and was used as a personal observatory and library for his son Humayun, finished only after he recaptured the fort. It is also one of the first observatories of Delhi, the first being in Pir Gharib at Hindu Rao at Ridge built in 14th century by Firoz shah Tughlaq. The tower is topped by an octagonal chhatri supported by eight pillars and decorated with white marble in typical Mughal style.
Inside there are remnants of the decorative plaster-work and traces of stone-shelving where, presumably, where the emperor's books were placed.This was also the tragic spot where, on 24 January 1556 Humayun fell from the second floor to his death. He slipped while hasting to the evening prayers, following his hobby of astronomical star gazing at the top of this private observatory. He fell headlong down the stairs and died of his injuries two days later.
Several other monument also lie around the complex, like Kairul Manzil, mosque built by Maham Anga, Akbar's foster-mother, and which was later used as a madarsa. Sher Shah Suri Gate or Lal Darwaza, which was the South Gate to Shergarh, the city he founded, also lies opposite the Purana Qila complex, across Mathura Road, south-east of the Kairul Manzil.