Who started his career as a trumpeter in the Bengal Horse Artillery. In September 1829, he left the British, and joined Maharaja Ranjit Singh's army as a gunner, eventually rising to the rank of colonel. He took part in the battle of Peshawar (1834) and the battle of Jamrud (1837). He accompanied General Ventura on his hill campaign of 1840-41, and helped the British in forcing their way through the Khaibar Pass in 1842. He had also served in a civilian capacity as kardar (revenue officer) of Gujrat for two years (1835-36).

John Holmes had simultaneously been acting as a British spy and supplying secret information to the Ludhiana Political Agency. After the first Anglo-Sikh war, he was, as a reward for his services, retained in the Sikh army when most of the other European officers were given their discharge. He was posted at Bannu where, in October 1848, the Sikh troops under his command mutinied and killed him for his treasonable conduct.

Source: Encyclopaedia of Sikhism, Harbans Singh