'Wantage' was an Allied deception plan associated with 'Overlord' and other later operations suggesting that the Allies had sufficient strength in the eastern and western parts of the Mediterranean to undertake large-scale operations against targets in southern Europe (February 1944/10 May 1945).

The plan was designed to persuade the Germans that the Allied forces in the Mediterranean theatre were 33% larger than they actually were, and those in the Middle East 100% larger than their actuality, and therefore that Germany needed to retain in southern Europe all the formations already deployed in these theatres, and indeed to reinforce them from western Europe or the Eastern Front.

The notional order of battle in its first iteration therefore included, outside Italy, 39 divisions (18 of them notional) in six corps (all notional) and one notional army. Early in June 1944 the plan, under the supervision of Brigadier Dudley W. Clarke’s 'A' Force as a development of the already-running 'Cascade', was enlarged into a second iteration so that the notional order of battle included all the French forces in the theatre.

In July 1944, with the Allied 'Dragoon' (i) landings in the south of France scheduled for the following month, it became desirable for the notional order of battle to be reduced, and to this end the plan entered its third iteration. In this, the French strength was reduced, Lieutenant General Alexander McC. Patch’s US 7^th Army was also trimmed and earmarked for the training that would suit it for deployment to Italy, and the forces in the eastern Mediterranean were retained at their supposed strength while a force centred on a notional Polish III Corps was readied for operations round the coast of the Adriatic Sea. Finally, in August and during the approach to 'Dragoon', the order of battle was again modified to include all the French forces which the Germans would encounter in 'Dragoon' and subsequent operations in southern France.

After the launch of 'Dragoon' (i), the need for 'Wantage' largely disappeared, and it was decided to end the plan, which in fact proved to be a slow and difficult process which had to be undertaken without endangering the secret channels which had been used to ensure that the Germans believed that they had penetrated the Allied planning. The notional formations and units were slowly transferred to India, broken up as replacements for other formations and units, converted into garrison troops, transferred to England, or converted (generally converted back) into static headquarters: the whole process was rendered all the more difficult as large numbers of the formations and units had featured in Allied deception plans for a considerable time.

Under the modified third iteration of 'Wantage', which came into existence during December 1944, the only formations which were allowed to survive were the notional British XIV Corps, now comprising the fictitious 42^nd and 57^th Divisions, which became a reserve corps trained in mountain warfare for use when the Allied forces in Italy reached the Alps; the notional British 5^th Airborne Division, which became a theatre reserve to maintain a latent threat against any German-occupied territory within range of current transport aircraft; and the notional British 34^th Division in the Middle East, which was to be ready for movement to Italy or the Adriatic at need.

Since these few notional units were kept alive until the end of the war, 'Wantage' survived to 10 May 1945. 'Cascade' and 'Wantage' had been at the heart of the Allied deception efforts in the Mediterranean theatre for some 3.5 years, and had been remarkably successful in their strategic deception roles. The success of 'Wantage' was made fully evident by the German order of battle maps which fell into Allied hands ever more frequently after the fall of Rome in June 1944, for almost every 'Cascade' and 'Wantage' formation and unit eventually found their way onto them. Especially gratifying to Clarke and the other 'A' Force personnel was the puzzlement of one German general who, during post-war interrogation, wondered why Field Marshal the Hon. Sir Harold Alexander had not made use, for the crossing of the Po river, of the 5^th Airborne Division, which did not even appear in the German roster until very near the end of the war.