When Allied forces landed on D-Day, the Jedburgh teams went into action behind German lines. These usually three-man teams, often composed of one British, one American and man one from the country into which they were sent to operate, spread chaos and confusion in the enemy's rear. Working with the marquis and other resistance groups, mainly in France, but also later in the Low Countries, the Jedburgh teams, each of which included a radio operator, were the vital link between the local groups and Allied high command. Their other main function was to organise airdrops of arms and equipment from the Special Operations Executive, via the RAF, to the resistance forces. This official history details the formation and the selection of these all-volunteer teams. It also details how the men were trained in parachuting, amphibious operations, skiing, mountain climbing, radio operations, Morse code, small arms, navigation, hand-to-hand combat, explosives, and espionage tactics. It also spells out the objectives of the Jedburghs. This was to impede the movement of the enemy's reserves to the battle front; to disrupt the enemy's lines of communication in the rear areas; and to compel the Germans to hold large reserves back from the front to contain the resistance operations. They provided leadership to resistance groups who had lost their own leaders and helped focus efforts against the Germans where the Allied forces were meeting stiff opposition. The effect the Jedburgh teams had on Operation Overlord was enormous and this history details the objectives of each Jedburgh team and their successes. This section of the book also lists the personnel of each team. In addition to their offensive actions, the Jedburghs set up hospital installations in the rear areas and mopped-up any remaining enemy positions by-passed by the main Allied forces. The Jedburgh teams also cooperated with the resistance forces in the south of France in Operation Dragoon, while four Jedburgh teams were also deployed in the Market element of Operation Market Garden. Supreme Allied Headquarters estimated that the contribution made by the Jedburghs and the groups they supplied and assisted was the equivalent of 'at least' one army division in the landings in and in the liberation of France. AUTHOR: This official history was written for the relevant Government department by those involved in, or related to the, the events in question and draws heavily upon information and testimonies provided by those who participated in them. 16 b/w illustrations