Before the First World War, part of Knockaloe Moar farm had been used as a summer training camp for Territorial Army men.  After the outbreak of war in August 1914 many German, Austro-Hungarian and Turkish civilians resident in Britain were interned due to security concerns and public antipathy towards the citizens of enemy countries.  The numbers were soon swelled by the imprisonment of merchant seamen off foreign ships that had been captured or interned.


The Isle of Man was identified as a suitable location to intern such people, with Knockaloe Moar being selected as the main site once an existing summer camp for tourists proved inadequate.  Interned men began arriving here in November 1914 and the site grew to become the main internment camp for the British Isles, eventually housing over 23,000 men iliving in wooden barracks inside 23 compounds surrounded by barbed wire and guarded by 4,000 soldiers. The camp remained in use until 1919.


Following the war the camp was dismantled and sold off, with most of the timber buildings being shipped off the island: a small number became prefabricated dwellings, or were adapted for other uses.  Some of the camp infrastructure still survives below ground, but after the return of the land to agriculture the main above-ground evidence lies in the dry-stone field boundaries that consist of broken-up concrete once used as foundation material for the wooden huts.