The 4th Punjab Infantry Regiment was an infantry regiment of the British Indian Army formed on 18 April 1849 by Captain GG Denniss at Lahore as part of the Transfrontier Brigade, which became the Punjab Irregular Force (PIF) in 1851. The regiment was designated as the 57th Wilde's Rifles (Frontier Force) in 1903, and 4th Battalion (Wilde's) 13th Frontier Force Rifles in 1922. In 1947, it was allocated to the Pakistan Army, where it continues to exist as 9th Battalion The Frontier Force Regiment.

On the conclusion of the Second Anglo-Sikh War in 1849, when the Kingdom of Punjab was annexed by the British, 10 irregular regiments were formed, 5 cavalry and 5 infantry, from men who had served in the Sikh Army of the former Kingdom of Punjab, the so-called Khalsa Army, by order of Col. Henry Montgomery Lawrence, President of the newly created governing body, the Board of Administration of the Punjab. They were irregular as they were outside the regulations of the Regular Army of the Line in such matters as discipline, training, uniforms etc. These 5 regiments were thus some of the first to adopt khaki uniforms, known as drab, so suitable for the local barren landscape. The purpose of these regiments was to form together the Transfrontier Brigade, to maintain the frontier between the newly annexed territory and Afghanistan, known as the Northwest Frontier, which was subject to frequent breach by marauding warlike groups of Afghan tribesmen.
(See main article: North-West Frontier (military history))

The regiment was raised at Lahore, historic capital of the kingdom of Punjab, by Capt. George Gladwin Denniss II(1821–1862), of the 1st European Bengal Fusiliers, appointed on 18 April 1849. Capt. O. Marshall, however, of the Madras Native Infantry became its first commandant, resigning on 19 March 1850, from which time Denniss took command until 25 February 1851. The regiment consisted in the first instance of 60 trans-Indus Pathans, followers of Dewan Mulraj, who had delivered themselves up as prisoners to the British Government on the capture of Multan, 200 men of Sardar Dhara Singh's Regiment and 300 men of Col. Shere Singh's Regiment. A number of the Fateh Paltan also were, by order of Sir Henry Lawrence, drafted to the regiment. The regiment's subsequent commander Lt-Col. Wilde wrote in 1860:

I have no hesitation in asserting that duty is carried on in the (Regiment) as strictly as in the Line. Compared with the Sepoy of the Bengal Army, there is a marked difference in the address and manners of these Northern men, assimilating somewhat to the more manly bearing of our own Soldiers....I have never heard any officer accuse them of want of discipline or subordination, and I believe in no Native Army has a strict and ready obedience to the orders of their superiors been carried out with greater success....It was in this Force that the Pathan, Jatsikh and Dogra was first taught to serve in the ranks of the British Army; and it was in these Regiments that the Afreedees and other Afghan tribes were gradually reduced to obedience, and are now as well behaved as any of our Native Soldiery.

The earliest record of such an oath is that recorded by Capt. Wilde, when in command of the Regt., from 1853:

I....inhabitant of....son of....swear by the Gooroo Grunth Sahibjee (holy scripture of Sikhism) and if I tell a falsehood may the Gooroo Grunth Sahib cause misfortune to descend upon me, that I will never forsake or abandon my Colours, that I will march wherever I am directed whether within or beyond the Company's Territories, that I will implicitly obey all the orders of my Commanders, and in everything behave myself as becomes a good Soldier and faithful servant of the Company, and failing in any part of my duty as such I will submit to the penalties ascribed in the Articles of War, which have been read to me.

The Regiment remained at Lahore until November 1850, the chief event of importance during this time being an inspection on 5 December 1849 by the Governor General, Lord Dalhousie. On 24 November 1850. the regiment, under the command of Capt. Denniss, marched from Lahore to Kohat via Shahpur and Kalabagh, through the Shakardarrah Pass, escorting 6 lakhs of rupees, arriving at Kohat on 8 February 1851. Shortly after their arrival the regiment was inspected by Brigadier Hodgson, commanding the Punjab Irregular Force. Denniss relinquished his command on 31 March 1851, to rejoin the 1st European Bengal Fusiliers, passing command to Capt. G.W.G.Bristow(1/4/51-21/10/52), thence to Capt. T.P.Walsh(22/10/52-20/2/53), thence to Capt. Alfred Thomas Wilde (21/2/53-10/3/62), who forms a central role in the history of the regiment.

Lt. Alfred Thomas Wilde of the 19th Madras Infantry, whose name was given in 1903 to the regiment as part of its official title, was appointed second in command on 4 April 1851, and joined 4 days later, being appointed commandant on 19 November 1851.