Due to a variety of grievances, in April and May 1857 large numbers of Indian troops rebelled against the orders of their East India Company officers and significant areas quickly fell under their control, including the city of Delhi by mid-May. Gurkha troops of the Sirmoor Battalion, which would later go on to become 2nd King Edward VII’s own Gurkha Rifles (the Sirmoor Rifles), were heavily involved in the British attempt to retake the city in late 1857. At the Siege of Delhi the Gurkhas of the Sirmoor Battalion fought side by side with their British comrades repulsing the rebels' onslaught on Hindoo Rao’s House. Finally on 14th September 1857 they stormed one of the gates of Delhi and with other troops lifted the siege.
In order to maintain communication between British and Nepalese troops, British officers from the forces of the East India Company were attached to Nepalese units for the duration of the campaign. One such officer was John Francis Slade Gully, who was attached to a unit of Nepalese army troops, which were part of a unit known as Jounpore Field Force, in December 1857. He remained attached to the unit throughout 1858 and was later presented with an engraved silver cup from ‘the civilians of the Jounpore Officers Mess’ in recognition of his time with them. This cup is now in the possession of the Gurkha Museum.