'Apostle' (i) was the Allied plan for the return to German-occupied Norway after the invasion of the European mainland had proved successful, the German forces had surrendered in their entirety, and all organised German resistance in Europe had ended (12 May/31 August 1945).

The Allies had been developing plans for the occupation of Norway since 1943 as 'Apostle' for implementation after Germany’s surrender. As initially conceived, the plan was based on Force 134 as the occupation force. This comprised Free Norwegian troops stationed in Scotland, as well as a British contingent (initially Major General N. M. Ritchie’s [from November 1943 Major General E. Hakewill-Smith’s] 52^nd Division), a few American troops, and some 12,000 Norwegian police troops currently stationed in neutral Sweden. In the event of an emergency, such as continued German resistance within Norway, it was arranged that the Supreme Headquarters Allied Expeditionary Force would deploy troops into Norway from Germany. The entire operation was controlled by General Sir Andrew Thorne’s Scottish Command.

After a number of British special forces raids in Norway during 1941, Adolf Hitler had ordered a major reinforcement of German strength in Norway, and the British hoped that Thorne, whose capabilities were known to be admired by the German leader, as head of Scottish Command would 'help to focus the Führer’s attention on the threat posed to Scandinavia' in general, and to Norway in particular.

Two separate scenarios were considered in planning 'Apostle'. The first was 'Rankin C (Norway)' based on the assumption that all German forces occupying Norway would surrender as part of a more general unconditional surrender by Germany. The second was 'Rankin B' based on the assumption that there was no surrender and that only parts of Norway would be abandoned by the Germans in order to reinforce their troops stationed in north-western Europe against Allied advances there. In this latter scenario, it was anticipated that Force 134 would meet determined German resistance.

The development of plans for the liberation and administration of Norway was complicated by the difficulty of predicting whether or not the Germans decided to oppose landings, and also by the likely extent of the damage resulting from Allied bombardments and German 'scorched earth' demolitions. As a result, planning for the administration of Norway was detailed yet very flexible.

Either of the two 'Rankin' scenarios would be difficult for Thorne to accomplish, however, as the troop strength allocated to Force 134 was very small as, from a time late in 1943, most military resources were dedicated to the campaign in North-West Europe. In September 1944 Thorne was even deprived of 52^nd Division, which was attached to Lieutenant General Lewis H. Brereton’s Allied 1^st Airborne Army for 'Market' and 'Garden'. Thorne was later allocated Major General R. E. Urquhart’s 1^st Airborne Division, but as a result of the heavy losses which it suffered in 'Market' this formation was not considered combat-capable once again until 1 May 1945 after it had received large numbers of replacements. For greater strength Thorne had therefore to place great reliance on the Milorg, the Norwegian military resistance movement.

During this whole process the Allied civil affairs planners maintained very close contact with the Norwegian government-in-exile, which was based in London, as well as on the Milorg. As a result, by the end of the war the Milorg had been preparing for the arrival of an Allied force for some time: its 40,000 members were well-armed and trained, and led by more than 100 Special Operations Executive agents parachuted into Norway, and it was prepared to prevent any possible sabotage of key communication centres and other important facilities by the Germans.

Within the overall 'Doomsday' scheme, the 'Apostle I' operation was implemented on 12 May 1945, four days after the surrender of German forces, when the advance guard of the Special Air Service Brigade (HQ Special Air Service Brigade as well as the 1^st and 2^nd Special Air Service) arrived at Stavanger under the command of Brigadier J. M. Calvert. By the end of the month the brigade had 845 men and 150 Jeeps in Norway, and was well advanced in its task of accepting the surrender of the first of some 172,000 German troops in the country. The brigade was based at Bergen, and encountered resistance only from Quislings (Norwegian collaborators of the Nazis) before returning to the UK at the end of August.