Salimgarh Fort was built in 1546 AD, in Delhi, in a former island of the Yamuna River, by Salim Shah Suri, son of Sher Shah Suri. There was a pause in Mughal rule when in 1540 AD Sher Shah Suri defeated the Mughal emperor Humayun and established the Sur dynasty rule in Delhi. Sur dynasty rule lasted till 1555 AD when Humayun regained his kingdom by defeating Sikander Suri, the last ruler of the dynasty. During the Mughal period, in later years, while building the Red Fort and Shahjahanbad, several Mughal rulers reigned, including Emperor Shahjahan, who is credited with completing Shahjahanabad in 1639 AD had camped at the fort. It is said that Humayun had camped at the fort for three days before launching his successful attack for recapturing Delhi.

The Red Fort or Lal Qila is a historic fort in the Old Delhi neighbourhood of Delhi, India, that historically served as the main residence of the Mughal emperors. Emperor Shah Jahan commissioned construction of the Red Fort on 12 May 1639, when he decided to shift his capital from Agra to Delhi. Originally red and white, its design is credited to architect Ustad Ahmad Lahori, who also constructed the Taj Mahal. The fort represents the peak in the Mughal architecture under Shah Jahan and combines Persian palace architecture with Indian traditions.