Brigadier Dudley Wrangel Clarke, was an officer in the British Army, known as a pioneer of military deception operations during the Second World War. His ideas for combining fictional orders of battle, visual deception and double agents helped define Allied deception strategy during the war, for which he has been referred to as "the greatest British deceiver of WW2". Clarke was also instrumental in the founding of three famous military units, namely the British Commandos, the Special Air Service and the US Rangers.

The Commandos, also known as the British Commandos, were formed during the Second World War in June 1940, following a request from Winston Churchill, for special forces that could carry out raids against German-occupied Europe. Initially drawn from within the British Army from soldiers who volunteered for the Special Service Brigade, the Commandos' ranks would eventually be filled by members of all branches of the British Armed Forces and a number of foreign volunteers from German-occupied countries. By the end of the war 25,000 men had passed through the Commando course at Achnacarry. This total includes not only the British volunteers, but volunteers from Greece, France, Belgium, Netherlands, Canada, Norway and Poland. The United States Army Rangers and US Marine Corps Raiders, Portuguese Fuzileiros Portuguese Marine Corps were modelled on the Commandos.