Pioneers were originally part of the artillery branch of European armies. Subsequently, they formed part of the engineering branch, in the logistic branch, part of the infantry; or comprised a branch in their own right.
The word pioneer is originally from France. The word (French: pionnier) was borrowed into English, from Old French pionnier, which meant a "foot soldier", from the root 'peon' recorded in 1523. It was used in a military sense as early as 1626–1627. In the late 18th century Captain George Smith defined the term as:
PIONEERS, in war-time, are such as are commanded in from the country, to march with an army, for mending the ways, for working on entrenchments, fortifications, and for making mines and approaches: the soldiers are likewise employed in all these things. Most of the foreign regiments of artillery have half a company of pioneers, well instructed in that important branch of duty. Our regiments of infantry and cavalry have 3 or 4 pioneers each, provided with aprons, hatchets, saws, spades, and pick-axes.
Pioneer regiments in the Indian Army
Extensive use was made of pioneers in the British Indian Army because of the demands of campaigning in difficult terrain with little or no infrastructure. In 1780 two companies of pioneers were raised in Madras, increasing to 16 in 1803 divided into two battalions. Bombay and Bengal pioneers were formed during the same period. In the late nineteenth century a number of existing Indian infantry regiments took the title and the construction role of pioneers. The twelve Indian Pioneer regiments in existence in 1914 were trained and equipped for road, rail and engineering work, as well as for conventional infantry service. While this dual function did not qualify them to be regarded as elite units, the frequency with which they saw active service made postings to pioneer regiments popular with British officers.
Prior to World War I each sepoy in a Pioneer regiment carried a pickaxe or a light spade in special leather equipment as well as rifle and bayonet. NCOs and buglers carried axes, saws and billhooks. Heavier equipment such as explosives was carried by mule. The unit was therefore well equipped for simple field engineering tasks, as well as being able to defend itself in hostile territory. During the War the increased specialisation required of Pioneers made them too valuable to use as regular assault infantry. Accordingly in 1929 the Pioneer regiments were taken out of the line infantry and grouped into the Corps of Madras Pioneers (four battalions), the Corps of Bombay Pioneers (four battalions), the Corps of Sikhs Pioneers (four battalions), and the Corps of Hazara Pioneers (one battalion).
All four Pioneer Corps were disbanded in 1933 and their personnel mostly transferred into the Corps of Sappers and Miners, whose role they had come to parallel. An Indian Pioneer Corps was re-established in 1943
Pioneers in the British Army
Historically, British infantry regiments maintained small units of pioneers for heavy work and engineering, especially for clearing paths through forests and for leading assaults on fortifications. These units evolved into assault pioneers. They also inspired the creation of the Royal Pioneer Corps.
During World War I, on paper at least, each division was allocated a pioneer infantry battalion, who in addition to being trained infantry were able to conduct pioneer duties. These pioneer battalions were raised and numbered within the existing infantry regiments; where possible recruits were men who possessed transferable skills from civilian life.
The Royal Pioneer Corps was a British Army combatant corps used for light engineering tasks. The Royal Pioneer Corps was raised on 17 October 1939 as the Auxiliary Military Pioneer Corps. It was renamed the Pioneer Corps on 22 November 1940. It was renamed the Royal Pioneer Corps on 28 November 1946. On 5 April 1993, the Royal Pioneer Corps united with other units to form the Royal Logistics Corps.
The Israeli army has a unit called the Fighting Pioneer Youth, in Hebrew Noar Halutzi Lohem or just "Nahal". This unit is an infantry brigade. The title of Israeli military pioneers is a back-derivation from the civilian term: The Israeli army's pioneers were formed in 1948 from Jewish civilian pioneers, i.e. settlers, who were permitted to combine military service and farming.
1st Jangi Auxiliary Pioneer Battalion (1000 strong), Nepalese Army
Jagannath Auxiliary Pioneer Battalion, Nepalese Army
First World War
Imperial German Army pioneers were regarded as a separate combat arm trained in construction and demolition or fortifications, but were often used as emergency infantry. One battalion was assigned to each Corps.
The Guard Pioneer Battalion 1. (6 companies with 20 large and 18 small flame-throwers each)
^Smith, George (1779). An Universal Military Dictionary, or A copious explanation of the technical terms &c. used in the equipment, machinery movements and military operations of an army. Whitehall, London: J. Millan.
^Carman, W.Y. (1969). Indian Army Uniforms under the British: Artillery, Engineers and Infantry. London: Morgan-Grampian.
^Gaylor, John (1992). Sons of John Company - the Indian and Pakistan Armies 1903-1991. Spellmount. ISBN0-946771-98-7.
^Summer, Ian (2001). The Indian Army 1914-1947. Oxford: Osprey. pp. 46–47. ISBN1-84176-196-6.
Dooley, Thomas P., Irishmen Or English Soldiers?: The Times and World of a Southern Catholic Irish Man (1876–1916) Enlisting in the British Army During the First World War, Liverpool University Press, 1995
Lane, Kerry, Guadalcanal Marine, University Press of Mississippi, 2004
Showalter, Dennis E., Tannenberg: Clash of Empires, 1914, Brassey's, London, 2004