The 21st Regiment of Bengal Native Infantry existed from the year 1857 to 1922. It was an infantry battalion formed by the British East India Company for service during the Sepoy Mutiny in 1857. The battalion was incorporated as a part of the Bengal Command. It was also under the Bengal Native Infantry, which was sub division of the Army of the Bengal province. The Bengal Army was amongst the 3 main Presidency Armies in British India and was the military of Bengal Presidency. . The conventional establishment of the regiments of Presidency Armies in British India was conducted through a chain of command. The infantry regiments were reformed and re-structured a number of times. All the regiments of the Bengal Army functioned under the administrative control of British East India Company.

Later the British Crown took over the Company and the Presidency Armies, namely the Bombay Army, the Bengal Army and the Madras Army, after the Government of India Act 1858 was formed. The battalion was also known as the 10th (Training) Battalion 14th Punjab Regiment and as the 21st Punjabis. Major General Sir Vere Bonamy Fane acted as the Colonel of the Regiment.

History of 21st Regiment of Bengal Native Infantry
The 21st Regiment of Bengal Native Infantry was established as the 9th Regiment of Punjab Infantry by the Honourable East India Company during the Great Revolt in 1857 in British India. The unit was formed by amalgamating 3rd Punjab Infantry and 6th Punjab Infantry. Later the military unit was renamed as the 25th Regiment of Bengal Native Infantry in 1861.

Military Operations of 21st Regiment of Bengal Native Infantry
The British Indian Infantry Regiment fought in the Abyssinian Campaign from the year 1867 to 1868. The unit later took part in Second Afghan War from 1878 till 1880. The 21st Regiment of Bengal Native Infantry was re-designated as the 21st Punjabis during the reforms of the British Indian Army under Lord Kitchener in 1903. The regiment was stationed in the Palestine and Egypt during the First World War. The battalion later provided armed service in the Battle of Megiddo in 1918. The British authorities raised a 2nd battalion of the regiment in 1917, which was dissolved after the end of the World War I.

Development of 21st Regiment of Bengal Native Infantry
The British administration in India restructured and renumbered the Indian army after the First World War. The various single battalion infantry regiments were unified to develop multi battalion regiments comprising of 4 to 6 battalions. The 21st Regiment of Bengal Native Infantry was merged with the 40th Pathans, 19th Punjabis, 20th Punjabis, 22nd Punjabis and 24th Punjabis regiment in order to develop the unit of 14th Punjab Regiment in the year 1922. In the same year, the regiment was renamed as the 10th (Training) Battalion of the 14th Punjab Regiment at Ferozepur. In 1943, it was again re-designated as the 14th Punjab Regimental Centre during the Second World War.

After the country gained freedom from the dominance of the British Empire in India in the year 1947, the former British India was divided into the Union of India and the Dominion of Pakistan through the Partition of India. The British Indian Army was shared amongst the 2 nations. The 21st Regiment of Bengal Native Infantry was assigned to Pakistan Army.

Designations of 21st Regiment of Bengal Native Infantry
The 21st Regiment of Bengal Native Infantry held many titles and designations through out its service under the British Indian Army. The different designations are mentioned below-
* 9th Regiment of Punjab Infantry - 1857
* 25th Regiment of Bengal Native Infantry - 1861
* 21st Regiment of Bengal Native Infantry - 1861
* 21st (Punjab) Regiment of Bengal Native Infantry - 1864
* 21st (Punjab) Regiment of Bengal Infantry - 1885
* 21st Punjab Infantry - 1901
* 21st Punjabis - 1903
* 1st Battalion 21st Punjabis - 1917
* 21st Punjabis - 1921
* 10th (Training) Battalion 14th Punjab Regiment - 1922
* 14th Punjab Regimental Centre - 1943