The barracks were built in the Fortress Gothic Revival style and named after Sir John Gaspard Le Marchant in 1878.

[1] Their creation took place as part of the Cardwell Reforms which encouraged the localisation of British military forces.

[4][5] In December 1944, it was where the "Devizes Plot" was hatched: this was an attempt at staging a mass escape of PoWs to attack London, stalling the Allied invasion of Germany and turning the tide of the war.

The conspirators were later relocated to Cultybraggan Camp, where "black" category prisoners i.e. the more ardent Nazis were imprisoned.

[8] Part of the site was still used as a Territorial Army Centre for the 1st Battalion, Wessex Regiment after the main barracks closed.