The Red Fort was at first referred to as "Qila-i-Mubarak" (the blessed fort), because it was the house of the royal family. The layout of the Red Fort was prearranged to retain and integrate this site with the Salimgarh Fort. The fortress palace is an important focal point of the medieval city of Shahjahanabad.
The preparation and aesthetics of the Red Fort represent the zenith of Mughal creativity which prevailed during the reign of Emperor Shah Jahan. This Fort has had many developments added on after its construction by Emperor Shahjahan. The significant phases of development were under Aurangzeb and later Mughal rulers. Important physical changes were carried out in the overall settings of the site after the First War of Independence during British Rule in 1857. After Independence, the site experienced a few changes in terms of addition/alteration to the structures. During the British period the Fort was mainly used as a cantonment and even after Independence, significant parts of the Fort remain under the control of the Indian Army until the year 2003.
The Red Fort was the fortress for Mughal Emperor Shah Jahan's new assets, Shahjahanabad, the seventh greatcity in the Delhi site. He enthused his capital from Agra in a move designed to bring prestige to his reign, and to provide ample opportunity to apply his ambitious building schemes and interests.