Let us recall what FORTITUDE said about the operations against Norway and the instructions which it gave for their execution. FORTITUDE provided for two landings on the Norwegian coast. One was to be made in the North by two divisions, which were subsequently to co-operate with Russian forces with the object of opening road and rail communication with Sweden. The other landing was to be made at Stavanger. An assault division, supported by commandos and parachute troops, was to capture the surrounding airfields to which long-range fighters were to be flown from the United Kingdom. This force was to be built up to a total of six divisions within three months, a part of the force being mountain trained. An advance to Oslo was to be made along the coast ‘by a series of mutually-supporting land and amphibious operations’. Diplomatic pressure on Sweden having meanwhile secured to us the use of Swedish airfields, an assault was to be launched against Denmark as soon as the Allies were firmly established in Southern Norway, their Air Forces operating from there and from Southern Sweden.
In view of our limited resources and of the fact that Scotland’s geographical position would make intensive reconnaissance by enemy aircraft difficult, it was agreed that elaborate visual misdirection, which was regarded as essential in the case of FORTITUDE SOUTH, would not here be necessary. Apart from one naval operation, the concentration of shipping in the Firth of Forth, and the display of a few dummy aircraft on Scottish airfields, FORTITUDE NORTH was executed by wireless and Special Means alone.
As is usual with plans of military deception, the foundation of FORTITUDE NORTH was provided by its Order of Battle. Before any real formation could be included one had to be satisfied that it was in the right place and that its location would continue to be suitable so long as the operation lasted. Before including imaginary formations one had to be sure that there were resources available to represent them on the air. An army was required to control both the operations; at least three army corps, one for the North and two for the South; and eight divisions, two for the North and six for the South, of which two had to be assault trained. In Scotland there were two British divisions, the 52nd Lowland Division near Dundee and the 3rd Infantry Division carrying out assault training in the Moray Firth in preparation for the real invasion. There was a large Polish force scattered over the Lowlands, a small Norwegian contingent at Brahan Castle near Dingwall, and a British Independent Brigade, the 113th, in the Orkneys. In addition there was the imaginary Fourth Army which had been created during the previous year to command the forces engaged in TINDALL. It was represented as an offshoot of Scottish Command having its headquarters a few miles from Edinburgh. It had ceased to operate, however, about November 1943. At that time, none of the real formations in Scotland, except the 3rd British Infantry Division, had been given any operational role connected with the invasion.
In Northern Ireland there was the 55th British Infantry Division (Lower Establishment) and an American Corps, the XV, with under command the 2nd, 5th and 8th United States Infantry Divisions. Although intended for ultimate employment in Normandy, the American force was not expected to leave until about three weeks after the invasion had started. The 55th British Infantry Division was performing garrison duties and might therefore be expected to remain in Ireland as long as we needed it. In Iceland there was the imaginary 55th United States Infantry Division which had been first reported about a year before by the British-controlled agents and had since been kept alive by COBWEB and BEETLE, the two double-cross agents who resided in that island. This division had never been represented on the air because it was held to be outside the normal range of the German intercept stations.
Formations printed in heavy type were imaginary
With these forces, real and imaginary, at our disposal, the Order of Battle was built up in the following manner. The Fourth Army was to be brought to life again to command the entire force. For the Northern operation the 52nd Lowland Division was to be trained to carry out the assault and elaborate preparations were initiated to simulate assault training, first by brigades and then as a whole division, in the Clyde. For the follow-up formation the imaginary American division in Iceland was chosen, it being supposed that it would sail direct to Narvik immediately after the assault had been made. It was to be strengthened by three imaginary ranger battalions which would come from the United States to Iceland before the attack was launched. The Norwegian contingent in Scotland was also to be included in the force. No real corps being available to command the Northern force, an imaginary one was to be created. This came into being in March 1944 and was known as the 7th British Corps. Its wireless traffic was simulated by signallers of the recently disbanded 9th British Armoured Division. For the Southern assault the 3rd British Infantry Division, which had already been assault training in the Moray Firth for some time and whose activities we supposed must by now have become known to the Germans, was chosen, its follow-up division being the 55th British Infantry Division, stationed in Ireland. To command these two divisions, the 2nd British Corps was selected. This Corps, which had been stationed for some time at Scotch Corner in Yorkshire, was, in fact, in process of disbandment. Arrangements were therefore made to retain a small skeleton staff and a sufficient number of signallers to simulate its continued existence, and for its name to continue to appear unaltered in the War Office records. Under command of this, the assault corps, was also placed the 113th Independent Infantry Brigade in the Orkneys. The role of follow-up corps for the Southern operation was to be filled by the American XV Corps in Northern Ireland, with its three infantry divisions under command, the presumption being that they would sail direct from Belfast. This still left us one division short, for it will be remembered that FORTITUDE laid down six divisions for the Southern operation. However, with wireless resources strained and with no other real division available, it was decided to make do with a total of five. The Polish Divisions in Scotland could not be used; not only would their employment in an expedition involving Russian co-operation have been unrealistic from a political point of view, but there were security objections. Finally, a naval assault force capable of lifting one division was required for the Northern attack. The naval assault force for the Southern attack was already provided by the real ‘S’ Assault Force associated with the 3rd British Infantry Division in the Moray Firth.
This grouping of forces having been agreed as the result of consultations between SHAEF, GHQ, Home Forces, and Scottish Command, SHAEF on 10th March, 1944, issued instructions for assembling the necessary wireless resources.1
The first criticism of these proposals came from the Navy, who expressed the view that it would not be possible, taking into account the wireless silence periods which, of course, imaginary as well as real forces had to observe, to make the assault training of the 52nd Lowland Division seem realistic in the time allotted. The sailing date for the Northern operation was therefore postponed until 15th May. The sailing date for the Southern assault remained at 1st May as originally planned. Then a more serious difficulty arose. The Joint Commanders decided that it would be necessary to carry out a full dress rehearsal in the English Channel a month before the invasion was due to take place. This was the exercise FABIUS to which reference has already been made. The 3rd British Infantry Division being one of the real assault formations would, of course, have to take part in it. This would presumably be noted by the enemy and would prove to them that the division was not intended for an assault on Stavanger at the very moment when we wanted FORTITUDE NORTH to be exercising its strongest influence, for it will be remembered that, according to our calculation, it took a German division three weeks to travel from Norway to France. The proposal to employ the 3rd British Infantry Division in FORTITUDE NORTH had always been open to criticism. Before the rehearsal was contemplated, the intention had been to simulate its wireless traffic in the Moray Firth after it had left for the South, and so make the Germans go on believing that it was bound for Norway until it actually appeared on the Normandy beaches. Taking the long view this was a dangerous proposal, for it might have provided the Germans with conclusive evidence that the whole of FORTITUDE NORTH was deceptive on the very day of the invasion. Be that as it may, the decision to hold Exercise FABIUS forced the issue and so the 3rd British Infantry Division was dropped from the Order of Battle and an imaginary one substituted. This explains the otherwise unaccountable absence of assault training from the programme of the imaginary 58th British Infantry Division, which was created to take the place of the real assault formation. It was generally agreed that an attack over the open Stavanger beaches required a higher degree of training than that which the 52nd Lowland Division was called upon to undertake in its northern deep-water fjord. The training programme for the Northern force had now been perfected with the sailing date of 15th May. The Southern operation had relied upon the participation of ‘S’ Force and the 3rd Infantry Division. These were now suddenly withdrawn. So we find in the final programme that the 58th Infantry Division and its associated naval assault force have to content themselves with a mere embarkation and disembarkation exercise in preparation for an invasion against ‘a very lightly defended part of Southern Norway’.2
The unexpected demand upon wireless resources caused by the creation of the 58th Infantry Division was met by 21 Army Group, who lent a detachment of 5 Wireless Group to represent it on the air. This newly formed division, which made its first appearance at Aberlour, south of Inverness, was supposed to have been recruited in the North and to have been built round a cadre of battle-trained officers and NCOs withdrawn from well-known Scottish regiments lately returned from the Mediterranean theatre. The formation sign, a pair of stag’s antlers, was suggestive of the Highlands. It will be remembered that we were at this time trying to conceal from the Germans the return from the Mediterranean of certain formations, including the 50th British Infantry and 51st Highland Divisions.3 There was always a danger of the enemy learning that troops belonging to these two formations had returned to the United Kingdom. In that event it was hoped that they might draw the conclusion for the time being at any rate, that these were merely drafts sent home to provide a cadre for the new division.
The Fourth Army wireless programme opened on 22nd March and by 6th April the whole network was active both in Scotland and in Northern Ireland.
Early in April two ‘CLH’ units, known respectively as Force ‘V’ and Force ‘W’, began their imitation of the naval assault forces in the Clyde. Force ‘V’ was to take part in the Northern operation and Force ‘W’ in the Southern.
From this point it will be easiest to follow the mounting of the two operations separately. Let us take the Southern assault first. Until 14th April the three brigades of the 58th Division were engaged in mountain training at Aviemore, Kincraig and Dufftown. On that date the whole Division moved south-west in the direction of Glasgow, conducting a series of mountain exercises as it went. On 23rd April it became associated on the air with its naval assault force. This association was confirmed on the 25th and 26th by the wireless traffic of an exercise in embarkation and disembarkation at Greenock. At the beginning of May the division retired to the east of Glasgow, where it could be heard continuing its training. Throughout this period the 2nd British Corps at Stirling simulated a number of signals and administrative exercises of its own. Meanwhile in Northern Ireland, the 55th British Infantry Division, the follow-up formation for the Southern assault, and XV Corps, which was to provide the build-up, continued their normal training. In order to emphasise their operational connection, however, it was arranged that the British formation should take part in an exercise directed by the American Corps at the end of April.
Turning to the Northern assault force, any record of the 52nd Division’s activities is complicated by the fact that it was a real formation, and its real movements did not always correspond with its fictitious ones.4 For the purposes of FORTITUDE NORTH, it was required to show that the Division contained one assault and two follow-up brigades. It was decided to allot the latter role to the 155th and 156th Brigades, which were thus able, for the time being, to continue their real training without interruption. The 157th Brigade, on the other hand, which was allotted the assault role, was placed on wireless silence and represented by its signals as being in close association with the Combined Training Centre at Troon. By 12th April this brigade had established contact with Force ‘V’ in the Clyde, and on 24th April it was to be heard exercising in Loch Fyne. During a wireless silence period at the beginning of May the Division moved, in reality, from Angus to Kilmarnock. On 10th and 11th May a full-scale landing exercise with one assaulting brigade and two following-up brigades was simulated with Force ‘V’ in Loch Fyne. During this period the whole Division had to remain on wireless silence. Thereafter fiction and reality were able to coincide once more and the 52nd Division revealed itself with its Divisional Headquarters at Kilmarnock and its Brigades exercising in the neighbourhood.
The follow-up formation for the Northern attack, the 55th United States Division in Iceland, was, of course, imaginary. No link was established between it and 7th Corps Headquarters, but the volume of traffic on the United States link between ETOUSA and Iceland was increased. Like 2nd Corps, 7th Corps from the middle of April engaged in signals and administration exercises. During the wireless silence at the beginning of May, Headquarters 7th Corps moved from Dundee to Beith, a short distance south-west of Glasgow.
Thus, at the middle of May, we find all the land forces and all the naval assault forces destined for the two Norwegian operations assembled near the Clyde and ready to sail at short notice. The move of Fourth Army Headquarters from Edinburgh to Ayr, which it was hoped would complete this picture of imminent action, though already planned, had not yet taken place.
In addition to the assistance given by the two ‘CLH’ units in the Clyde, the Navy helped FORTITUDE NORTH in two other ways. First, on 26th April, C-in-C, Home Fleet, carried out a carrier-borne air reconnaissance operation off Narvik.5 Second, it was arranged with the Ministry of War Transport that surplus shipping should be berthed at Methil in the Firth of Forth, with the result that the average number of ships anchored there rose from twenty-six in the first week of April to seventy-one in the second week of May. The concentration was supposed to represent part of the build-up force.
During the second half of April and first week of May, the Royal Air Force, by the display of dummy aircraft and the manipulation of wireless traffic, simulated the transfer of four medium bomber squadrons from airfields in Suffolk to others in Eastern Scotland. At the same time a flight of eight real Spitfires was stationed at Peterhead, to which eight dummy Spitfires were added. This was to provide protective cover for the medium bomber force.
It was the opinion of the operational staff at AEAF that if we were going to attack Scandinavia, we should not begin softening raids until about three days before the attack. For this reason no cover bombing was carried out. Similarly the existing scale of reconnaissance over Norway by carrier-borne aircraft was considered adequate and therefore, apart from the naval operation already mentioned, no additional measures were proposed.