The Cover Plan for OVERLORD was given the name FORTITUDE. There were two parts to FORTITUDE – FORTITUDE NORTH AND FORTITUDE SOUTH. The aim of FORTITUDE NORTH was to convince the Germans of a threat against Norway. FORTITUDE SOUTH was designed to convince the Germans that the decisive assault force would be launched against the Pas de Calais area and that the Normandy landings (Operation NEPTUNE) were a diversionary operation.
A Home Forces Memo dated 14 December 1943 to Eastern Command outlined the elements of the Cover Plan relevant to Eastern Command: The aim of the plan was to:
To induce the enemy to believe that the main assault and follow up would be in or to the east of Pas de Calais and thereby encourage the enemy to maintain or increase his air and ground forces and fortifications in this area at the expense of others.
To keep the enemy in doubt as to the date and time of the actual assault.
During and after the main assault to encourage the enemy to maintain the largest possible air and ground forces in the Pas de Calais area for at least 14 days.
The deception was to be carried out using a variety of methods:
The simulation by deceptive wireless of additional amphibious forces training in the area
During the concentration of forces for OVERLORD, the simulation by deceptive wireless of additional forces concentrating for assault and follow-up.
Wireless silence was maintained during the final movements and build up of formations in the actual assembly and embarkation areas for the genuine assault.
A key element of FORTITUDE SOUTH was to persuade the Germans that the main invasion force would be the 1 U.S Army Group (FUSAG), positioned in South east England for a landing in the Pas de Calais area – FUSAG was a purely phantom force, this deception was known as Operation QUICKSILVER. The deception was maintained well after the true invasion force, 21 Army Group, had landed in Normandy in order to encourage the Germans to maintain a strong force in the Pas de Calais area. The following fictional units under FUSAG were notionally based in Suffolk at some point during QUICKSILVER:
US XXXIII Corps (HQ Bury St Edmunds)
- 11 US Infantry Division (HQ Bury St Edmunds)
- 48th US Infantry Division (HQ Woodbridge)
59th US Infantry Division (HQ Ipswich) – Part of US XXXVII Corps (fictional)
British 5th Armoured Division (HQ Newmarket) – Part of British VII Corps (fictional)
Below: Some of the fictional units, part of the fictional FUSAG associated with Suffolk:
US XXXIII Corps US XXXVII Corps US 59th Inf. Div US 48th Inf. Div
Camouflage policy varied between the Commands involved in OVERLORD with Eastern and South Eastern Command being areas of display.
Dummy Landing Craft
Dummy Landing Crafts were erected on the East and South East Coasts.
Deceptive lighting was used on hards and assembly areas to give the impression these were the actual locations to be used for the real assault. In Suffolk, deceptive lighting was established for Yarmouth / Lowestoft at Breydon Water, Oulton Broad and Benacre Ness and for River Orwell at Whitehall Farm and Trimley Marshes. These sites were ready by the start of May and were turned on at D + 2 (8th June) to suggest troops in the area. The lighting was increased in between 25th June and 5th July to suggest that troops were embarking before being toned down again between 6th to 30th July (however during this period of display the Yarmouth / Lowestoft displays were abandoned altogether) .
Fields of Deception, C Dobinson, Methuen 2000
Camouflage and Concealment – FORTITUDE, TNA
Wickipedia – FUSAG / XXXIII Corps