The 21st Kohat Mountain Battery (Frontier Force) was an artillery unit of the British Indian Army.

The 21st Kohat Mountain Battery was raised at Bannu by Lieutenant H Hammond on 1 February 1851 from horse artillery detachments of the Lahore Durbar, as part of the Punjab Irregular Force (Piffer).

The Piffers were a collection of regular units accreted for expeditionary operations in the Punjab Frontier and Afghanistan.

The Kohat Battery saw extensive service on the Frontier and took part in numerous operations including the Second Afghan War and the Tirah Campaign in 1897–98.

[1][2] During the First World War, the 21st Kohat Mountain Battery fought with great distinction at Gallipoli, Egypt, Mesopotamia and Persia.