Between March 1939 and April 1941, Nazi Germany overran almost the whole of continental Europe in a series of lightning campaigns. Some of the defeated troops managed to evade capture and set up guerilla units in rural areas or escaped to friendly countries. The hard pressed Allies welcomed this source of motivated manpower with open arms and these volunteers were either incorporated into existing units or formed into new ones. These emigre servicemen, fanatically anti-German and with priceless "in country" knowledge were valuable recruits for the various unconventional and clandestine warfare units such as 10th (interallied) commando and the SOE. This volume covers the largely ignored contribution of these volunteer units which served alongside the major combatants to help overthrow Nazi tyranny.