The Red Fort (usually transcribed into English as Lal Qil’ah or Lal Qila) is a 17th-century fort complex constructed by the Mughal emperor, Shah Jahan in the walled city of Old Delhi (in present day Delhi, India) that served as the residence of the Mughal Emperors. The design is commonly credited to Mughal architect Ustad Ahmad. The fort was the palace for Mughal Emperor Shah Jahan’s new capital, Shahjahanabad, the seventh city in the Delhi site. He moved his capital here 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. It served as the capital of the Mughals until 1857, when Mughal emperor Bahadur Shah Zafar was exiled by the British Indian government.
The fort lies along the Yamuna River, which fed the moats that surround most of the walls. The wall at its north-eastern corner is adjacent to an older fort, the Salimgarh Fort, a defence built by Islam Shah Suri in 1546. The construction of the Red Fort began in 1638 and was completed by 1648. The Red Fort has had many developments added on after its construction by Emperor Shah Jahan. The significant phases of development were under Aurangzeb and later under later Mughal rulers. It was designated a UNESCO World Heritage Site in 2007. The earlier Red Fort was built by Tomara king Anangpala, now known as the Qulb Mosque.