The time has come to turn our attention once more to Scotland and to follow the Northern operation to its conclusion. The reader will recall that, though the bulk of its forces were concentrated in the neighbourhood of Glasgow, the headquarters of Fourth Army were still near Edinburgh at the beginning of May. While it was important that we should sustain the Northern threat until the time of the invasion, and if possible beyond that date, certain factors militated against its continuance, at least on its present scale. The 2nd US Infantry Division had already been withdrawn from XV Corps and had moved from Northern Ireland to Tenby in South Wales, where it had replaced the 28th US Infantry Division. During May it would be necessary to transfer the naval deception units representing assault forces ‘V’ and ‘W’ for employment in the South. Finally the withdrawal of shipping from Northern ports would compel us to admit a reduction in the scale of the assault. With these considerations in mind, the position was reviewed at the middle of April.1 It was expected at that time that the 2nd Canadian Corps, which then formed part of the imaginary FUSAG, would be going overseas about eight days after the invasion began. Since shipping space and assault craft would now be inadequate for the requirements of Fourth Army as then constituted, it was suggested that a part of the Scottish force might be moved to the South-East of England to take the place of the Canadian formations in the FORTITUDE SOUTH Order of Battle. Not every formation in Fourth Army could, however, be used in a false role, in South-East England. XV Corps with the 5th and 8th US Infantry Divisions was due to move from Northern Ireland to the Midland counties at the middle of May, but its early transfer to Normandy precluded its employment in FORTITUDE SOUTH. The 52nd Lowland Division was prevented by its training programme from leaving Scotland and the employment of die imaginary 55th US Division in Iceland was considered impracticable. The 7th British Corps could have been used, but since its two divisions were tied down, it seemed better to leave it where it was. This left the 2nd British Corps with its two divisions, the real 55th British Infantry Division in Northern Ireland and the sham 58th British Infantry Division in Scotland. There was no difficulty about the 2nd British Corps and 58th British Infantry Division, as they were both imaginary and were provided with adequate deceptive wireless resources, but it was not so easy to make the real British division in Ireland available. After some negotiation with the War Office, it was agreed that the signals of this formation should be formed into an advance party and transferred to Scotland; where they could represent it on the air, the remainder being instructed to use low-powered sets in the divisions old location. It was accordingly arranged that the 2nd British Corps with its two divisions should be earmarked to fill the gap caused by the departing Canadians. It was proposed that this force should stage for a time near the Humber whence it could assist both the Northern and the Southern threats. It was thought wise to leave Fourth Army in Scotland for the present, as a senior headquarters was needed to command the 7th British and XV Corps so long as they were able to fulfil their present cover role in the North. Although XV Corps was about to move to England, it would be possible by placing these American formations on wireless silence and by representing them as being in their old locations, to include them in Fourth Army for some time after the date of their departure. During the week following 21st May a detachment of 3103 Signals Service Battalion was sent to Northern Ireland to give effect to this, and in that manner XV Corps remained ostensibly a part of Fourth Army until the end of June. A plan to give effect to these proposals was issued on 4th May.2 In accordance with this plan, the Scottish formations awaiting embarkation would continue to carry out exercises in the neighbourhood of Glasgow. Towards the end of the month Fourth Army Headquarters would move from Edinburgh to Ayr. At the same time the wireless nets of the 55th British Infantry Division would open at Dumfries. On 2nd June a large-scale Army exercise lasting some four days would take place, and on the 5th this exercise was to be interrupted by the order for the 2nd Corps and its two divisions to move to Lincolnshire. Throughout May this programme was adhered to, but as a result of a request from 21 Army Group that the transfer of the 2nd Corps should be advanced by three days, that formation and the two divisions under its command left on 2nd June, and accordingly the exercise did not take place. On 5th June 2nd Corps, still netted to Fourth Army, came on the air at Louth with the 55th British Infantry Division at Skegness and the 58th at Horncastle,3 and on the 6th a link was opened between 2nd Corps and FUS AG. We will leave its subsequent movements to a later chapter dealing with the Southern operation.
Meanwhile in the North the 113th Independent Infantry Brigade in the Orkneys, which had formed part of 2nd Corps, was brought under 7th Corps, while a link was opened between 7th Corps and the 55th US Infantry Division in Iceland. With this reduced force, it could not be pretended that the Scandinavian assault was still contemplated on the original scale. From now onwards, therefore, the operation was only to be undertaken in the event of a considerable weakening of German forces or of a total withdrawal.
Formations printed in heavy type were imaginary
When June came, it was in any case obvious that the force of FORTITUDE NORTH was spent. The battles in Normandy were already monopolising the attention of the enemy and presently the few remaining formations which had survived the regrouping of early June were to be withdrawn. On 30th June, since XV Corps was about to land in the beach-head, the detachment of 3103 Signals Service Battalion closed down in Northern Ireland. On 2nd July the 52nd Lowland Division was released from its fictitious role.4 At the middle of July Fourth Army and 7th British Corps were required to command forces in the reconstituted FORTITUDE SOUTH Order of Battle, and proceeded to England.5 A plan for keeping alive a very slender threat against Scandinavia which would have involved the transfer of the 55th US Infantry Division to Scotland was drafted, but never came into operation.6
Among the controlled agents, since Three had now left for London to help GARBO, the main burden fell, during the latter days of FORTITUDE NORTH, upon GARBO’s agent 3 (3). The Germans had regarded Three’s departure as a somewhat dangerous exposure of the flank: ‘If you consider it advisable to call Three to help you, please ask him to consider carefully if in this event the North will be well covered by 3 (3), since it is very possible that some action will start up also from those ports.’7 Nevertheless it was a risk which had to be accepted and by the middle of the month 3 (3) had moved to Glasgow, as being a more central position.
On his arrival in London Three had expressed the view that the initial attack of the European invasion would be against Norway. In this he was supported by 3 (3). GARBO, with his wider outlook, had been disinclined to accept their view, which he evidently regarded as somewhat parochial, though he had felt bound to add: ‘Nevertheless I take notice of this opinion since Three is in a better position than I am to assess this question due to what he has been able to see in his recent stay in the North.’8
3 (3)’s erratic behaviour during the next two or three weeks, while it succeeded in provoking a number of German questions which showed that they had not yet lost interest in the Clyde, was really part of the rather intricate plot connected with the invasion in the South, which has already been described in the last chapter. The only other Scottish news was provided by BRUTUS. On two occasions, once before and once after the invasion he confirmed that Fourth Army retained its independent role.9 He also told the enemy about the move South of 2nd British Corps and the consequent reorganisation of forces in the North.10 Thereafter apart from a first-hand account by 3 (3) of a Fourth Army exercise in Ayrshire,11 nothing more was heard from Scotland until the final dispersal of forces occurred in July, when GARBO made this appreciation: ‘There is something important which I wish to stress. If I recall correctly, the Fourth British Army was in Scotland with the concentration observed by 3 (3) in Motherwell, that is to say, together with 2nd Corps, the 55th and 58th Divisions. If, therefore, the British Army moves down, the only division left to effect the proposed attack against Norway will be 52nd Division. I therefore consider that an attack against Norway is impossible for the moment. My present observation goes to show how right I was when I expressed the opinion against the views of Three and 3 (3) that this operation would not then come off at that time of the year. I therefore consider that a state of alarm in Norway need no longer be maintained.’12
FORTITUDE NORTH did not end officially until 30th September, when the Combined Chiefs of Staff considered that owing to lack of German reserves one could no longer hope to contain enemy forces in non-active sectors such as Scandinavia, and that, in consequence, the cost of maintaining such threats would no longer justify the effort required.13 The 55th US Infantry Division and the three Ranger Battalions, the only surviving formations in the FORTITUDE NORTH Order of Battle,14 remained in Iceland until March 1945, when a report from BEETLE that the Americans were withdrawing may allow us to conclude that they left at that time for some unknown destination.15