Shergarh (The Citadel of Sher Suri)
In 1540 a sway of imperial power saw Babur's son Humayun getting defeated by Sher Shah Suri. Sher Shah established another capital city of Delhi. The City, known as Shergarh, was built on the ruins of Dinpanah that Humayun had set up. The remains of Shergarh is what you see today at Purana Qila. Once Humayun came back to power, he completed the construction and proceeded to rule from Shergarh. Firoze Shah completed the mosque of Jamali-Kamali, jamali's Tomb at Mehrauli.
What is known as the Purna Qila today, was the creation of Sher Shah when he wrested Delhi from Humayun in 1540, the second Mughal king. It was originally being built by Humayun as his capital Dinpanah. Sher Shah razed Dinpanah to the ground and started building his own capital introducing ornate elements in architecture. He died in 1556, while descending from the stairs of Sher Mandal, which is believed to have been used by him as a library. Delhi was won back by Humayun not very many years later in 1555 and he completed parts of the Purana Qila left unfinished by Sher Shah. The ruins of Humayun and Sher Shah's Qila left unfinished by Sher Shah. The ruins of Humayun and Sher Shah's creations are today a big tourist attraction. Humayun's Tomb(world heritage monument), one of the most impressive Mughal edifices, was built by Hamida Hanu Begum, the Humayun's widow. In the 1857 war of Indian Independence, the last Mughal emperor Bahadur Shah Zafar took refuge at Humayun's tomb along with three princes. But unfortunately, his forefather could not come to his rescue. It was from here that Captain Hodson captured him and he was finally exiled to Rangoon (now Yangon)