After the First World War, the 53rd Sikhs were grouped with the 51st, 52nd and 54th Sikhs, and the two battalions of Guides Infantry to form the 12th Frontier Force Regiment in 1922. The 53rd Sikhs became 3rd Battalion (Sikhs) of the new regiment. For their excellent performance during the First World War, they were made a 'Royal' battalion in 1935. During the Second World War, 3/12 FF served with great distinction in the Italian East Africa, Sicily, Italy and Greece. In 1947, the Frontier Force Regiment was allotted to the Pakistan Army. In 1948, 3/12 FF fought in the Kashmir War against India. In 1956, the Frontier Force Rifles and the Pathan Regiment were merged with the Frontier Force Regiment, and 3/12 FF was redesignated as 5 FF. During the Indo-Pakistan War of 1965, the battalion greatly distinguished itself in the Battle of Khem Karan, while during the Indo-Pakistan War of 1971 it served in Kashmir. The unit was awarded 5 Sitara-e-Jurrats and 4 Tamgha-e-Jurrats during its post-independence service