The Delhi Fort also known as Lal Qil'ah, or Lal Qila (Hindi: लाल क़िला, Urdu: لال قلعہ) meaning the Red Fort, located in Delhi, India and became a UNESCO World Heritage Site in 2007.The Red Fort and the city of Shahjahanabad was constructed by the Emperor Shah Jahan in 1639 A.D. The layout of the Red Fort was organised 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 planning and aesthetics of the Red Fort represent the zenith of Mughal creativity which prevailed during the reign of Emperor Shahjahan. 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, a significant part of the Fort remained under the control of the Army until the year 2003.
The Red Fort was the palace for Mughal Emperor Shah Jahan's new capital, Shahjahanabad, the seventh Muslim city in the Delhi site. He moved 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.
The fort lies along the Yamuna River, which fed the moats that surround most of the wall. The wall at its north-eastern corner is adjacent to an older fort, the Salimgarh Fort, a defense built by Islam Shah Suri in 1546. Construction on the Red Fort began in 1638 and was complete by 1648.
On 11 March 1783, Sikhs entered Red Fort in Delhi and occupied the Diwan-i-Am. The city was essentially surrendered by the Mughal wazir in cahoots with his Sikh Allies. This task was carried out under the command of the Sardar Baghel Singh Dhaliwal of the Karor Singhia misl.