The Diwan-i Khass from the west, (top right), The interior of the Diwan-i Khass (bottom right) - 1843.

[From 'Reminiscences of Imperial Delhi’, an album consisting of 89 folios containing approximately 130 paintings of views of the Mughal and pre-Mughal monuments of Delhi, as well as other contemporary material, with an accompanying manuscript text written by Sir Thomas Theophilus Metcalfe (1795-1853), the Governor-General’s Agent at the imperial court. Acquired with the assistance of the Heritage Lottery Fund and of the National Art-Collections Fund.]

The Dewan-e-Khafs or Audience Hall for the Nobility was constructed by the Emperor Shah Juhan, by whom the Royal Palace was also built. It is situated at the upper end of a spacious Square, elevated upon a Terrace of white Marble about four Feet in height. The Dewan-e-Khafs in former times was adorned with Excessive Magnificence and though plundered by Nadir Shah, the King of Persia during his invasion in 1738/9, and subsequently mutilated by the Barbarous Hordes of Mahrattas during the later end of the past and beginning of the present Century, still retains sufficient Beauty to render it the object of Admiration.

The dimensions are said to be 150 feet in length by 40 in breadth. The roof is flat supported by numerous Columns of white Marble, richly ornamented with inlaid flower Work of different coloured Stones, chiefly Cornelian. The Cornices and Borders being decorated with Frieze and Sculptured work. The Cieling [sic] was formerly incrusted with a rich Foliage of Gold and Silver Work throughout its whole Extent. This during the Period of Anarchy was removed and an imitation Ceiling, which still exists, substituted.In the interior of the Building and in the Cornice are the following lines written in the Persian Character in letters of Gold:
[In Persian]: agar firdaus bar rui zamin asthamin ast va hamin ast va hamin ast
Ugur Firdoce bur Rooe Zumeen ust.
Humeen usto Humeen usto Humeen ust.
If there be a Paradise upon Earth.
It is this. It is this. It is this.

[The Diwan-i Khass from the west with canopies and screens. The Red Fort was commissioned by Shah Jahan (r.1627-58) in 1639, it took nine years to build and was the seat of the Mughal power until 1857, when Bahadur Shah Zafar, the last Mughal emperor was dethroned and exiled. Part of the palace complex, the Diwan-i-Khas, or Hall of Private Audience, was where the emperor would consult with his advisors and meet important visitors. The hall was built entirely of white marble inlaid with precious stones. The hall’s ceiling was once silver, which was removed by the Marathas and the spectacular Peacock throne was taken by Nadir Shah of Persia in 1739.]
Inscribed: naqsha-i divan-i khass andarun-i qil‘a-i shahjahanabad. Mazhar ‘Ali Khan.[The interior of the Diwan-i Khass, with qanats concealing the Khwabgah and the Scales of Justice.]
Inscribed: naqsha-i andarun-i divan-i khass dar qil‘a-i shahjahanabad taraf-i shamal hast. ‘amal-i Mazhar ‘Ali Khan.

Source : British Library