Risaldar Jagat Singh, 12th Cavalry, and Ressaidar Man Singh, 21st Cavalry, by Philip de László, 1916

This double portrait seems to have been done for the artist's own pleasure, and was in his studio at his death.  From the De László Archive Trust's catalogue raisonné:

Risaldar Jagat Singh joined the Indian Army 26 February 1905 as a Jemadar (junior Indian officer) in the 12th Cavalry and was promoted to Ressaidar 11 April 1916 in the 18th King George's Own Lancers. He was subsequently promoted Risaldar 11 August 1918 when he is listed in the 12th Cavalry but still attached to the 18th. It is likely that he was acting at that rank in 1916 when the portrait was painted, or he inadvertently gave himself the wrong rank, when signing the artist’s Sitters’ Book.

Ressaidar Man Singh joined the Indian Army 1 March 1890 as a Sowar (a cavalry trooper). He was promoted to Jemadar 1 May 1910 in the 21st Prince Albert Victor's Own Cavalry before further promotion to Ressaidar 11 April 1916 in the 20th Deccan Horse. He seems not to be listed after 1917, though he is not listed among the dead in the Indian Army Lists. The sitter is also known to have been awarded the Indian Order of Merit 3rd Class, 3 November 1894 for his gallantry in the Warziristan Action at Wano, the north-west frontier of India.