On the 26 November 1901, the Military Prison Staff Corps was formed within the British Army. The purpose of the corps was to run the Army’s prisons and detention establishments. In 1906, the corps was renamed the Military Provost Staff Corps. The Depot for the corps was shared with that of the Corps of Military Police, being located at Mytchett Hutments, Ash Vale, Hampshire.

The origins of the corps date back to the spring of 1895, when a committee was formed under the chairmanship of Lord MONKSWELL to ‘consider the regulations affecting the discipline and diet of soldiers confined in military prisons and to report whether any changes were desirable’.

Prior to the formation of the committee, garrison troops were used to provide the guards for military prisons. The prisoners were treated harshly, with hard labour being a frequent task given to prisoners. One of the key members of the committee was Lieutenant Colonel Michael Clare GARSIA. He had been acting as the Inspector-General of Military Prisons, a post he assumed in 1898. GARSIA was concerned with the military prison system. The skills and ability of the guards was very variable, with very few possessing much in the way of compassion. GARSIA realised that improvements in the system could only be achieved by recruiting staff who were ‘possessed of the military spirit and thoroughly efficient as instructors’. Therefore, he devised a set of qualities and qualifications required for a new corps of military prison staff, who he saw should be experienced non-commissioned officers.

The Military Provost Staff Corps quickly became established across the globe wherever British soldiers were stationed. The military prisons were redesignated as detention barracks, with the prisoners now known as ‘Soldiers Under Sentence’.

In 1940, the main military prison was to be found at Aldershot. Known as ‘The Glasshouse’, it was built in 1870 to house soldiers sentenced for military offences. Its name came from the large, glass, lantern roof on the building. The term then came to be used for all military prisons. The prison was designed for one-hundred and fifty prisoners, but by 1946, it housed over four-hundred.

During the Second World War, there were additional prisons and detention barracks at Shepton Mallet (opened in 1939) and Barlinnie in Glasgow. Due to the outbreak of the war, two detention barracks for deployment in the field had been formed. In addition, members of the Military Provost Staff Corps ran prisons and detention barracks at Malta, Jamaica, Singapore, Gibraltar, Hong Kong, Tientsin, Shanghai, Cairo, Khartoum and in Palestine.

At about 5.00 pm the 23 February 1946, a riot broke out at the Aldershot ‘glasshouse’, which lasted nearly twenty-four hours. This resulted in serious damage to the building. Consideration was given to rebuilding the Aldershot glasshouse, but prisoners were moved to other military prisons.

As of 2013, there is just one military prison, the Military Corrective Training Centre at Colchester. The last military prison, at Shepton Mallet, closed in 1966. In 1992, the Military Provost Staff Corps was incorporated into the Adjutant-General’s Corps.

For anyone interested in this corps, I recommend reading:
McENTEE-TAYLOR, Carole, Military Detention Colchester From 1947 – Voices from the Glasshouse Barnsley, Pen & Sword Military 2014 i – xii 250 pp ISBN 978 1 78340 059 1 (hbk)