Chapter 11: The Decision To Evacuate, 26th May, 1940
Before resuming the account of British operations which was interrupted to describe the happenings at Boulogne and Calais, it may be well to take stock of the situation on the morning of May the 26th as it appeared at the time to the Commander-in-Chief.
He knew that the British and French forces were enclosed by two German Army Groups in a pocket which with its open mouth at the Dunkirk coast hung down to the River Sensée. he knew that the forces which held its margins were stretched out on a front of 128 miles and that though in some sections the front was held by French troops and in some was held jointly, yet his own troops were extended over 97 miles. He knew now that the 1st Armoured Division, description of whose movements must be postponed to later chapters, would now never reach him, for elements were at Calais and the rest away south of the German-held breach in the French front. He knew that no reinforcements were being sent out and that ammunition and supplies were running short, though as many as possible of the non-fighting troops were being evacuated. Finally he knew that the Belgian Army on his northern flank was in danger of being isolated and was nearing the point of collapse. To prevent the enemy from sweeping round his left flank between the British Expeditionary Force and the sea he had sent the 5th and 50th Divisions to the danger spot. They could not now join General Altmayer’s forces in a counter-attack southwards; whether or not the French would attack without British support he did not yet know. Nor did he know any details of the complementary attack from the south which was an essential part (in his view the major part) of the Weygand Plan, much less did he know that the attack from the south had in fact been cancelled.
The British Expeditionary Force was indeed in a desperate situation, more desperate even than bare facts revealed. For the forces holding the long front were greatly outnumbered by those opposed to them. In the north-east where the 5th and 50th Divisions were moving into the gap between Comines and Ypres three German divisions of Army Group B were seeking to break through.(1) In the west, apart from improvised detachments, there were one Regular division (the 2nd) and three Territorial divisions (the 48th, 44th and 46th). Of the latter, the 48th and 44th had at this time only two brigades each on this front, and the 46th, though fighting stoutly, was
the third of the divisions which had been sent out originally to continue training and for labour duties. There were also some of the mechanised cavalry and the 1st Light Armoured Reconnaissance Brigade. Ranged against this slender array the German Army Group A had six armoured and four motorised divisions, with more in rear.(2) These details of the enemy forces were not fully known to Lord Gort but he knew that nine or ten armoured divisions and many others were operating on this flank and that if they were to be held off, the total frontage which he had to defend must be shortened.
Early on this Sunday morning Lord Gort informed the Secretary of State for War that he had dispatched the 5th and 50th Divisions to fill the gap which the Belgian withdrawal northwards was creating.(3) He and General Pownall then went to General Blanchard’s headquarters where they learned that the French general had already decided to cancel the planned attack southwards: orders to that effect had been issued just before midnight but had not reached Lord Gort’s Command Post before he left(4) General Blanchard’s operation order No. 30 was as follows:
I. The enemy has crossed the Lys on both sides of Courtrai and has reached Menin, Iseghem, Ingelmunster.
The British divisions which were to have attacked towards Marchiennes–Péronne are no longer available for this purpose.
II. In consequence, the attack envisaged in the Marchiennes–Péronne direction will not take place.
The First Army, the BEF and the Belgian Army will regroup progressively behind the water-line demarcated by the Aa Canal, the Lys, and the ‘Canal de Derivation’ so as to form a bridgehead covering Dunkirk in breadth.
This bridgehead will be held with no thought of retreat.
III. The First Army will start its withdrawal on the 26th May, bringing its reserves back to the north of the Scarpe.
The withdrawal from the Sensée–Escaut line is intended to take place during the night of the 26th/27th.
The First Army will put one light mechanised division in the area east of Ypres, to go into action towards Courtrai (special order).
IV. The Belgian Army will make every effort to reduce the pocket achieved by the enemy north of the Lys at Courtrai.
The light mechanised division put in east of Ypres can act on its own behalf on the orders of the commander of the group of armies.
V. The forces at the disposal of Admiral Nord will throw back the enemy to the west of Aa, where the enemy has crossed the river, and will afterwards be responsible for the defence of the river.
Signed: BLANCHARD.1(5)
Thus the northern thrust envisaged in the Weygand Plan was now
finally abandoned, and since, as we have seen, the southern thrust had been abandoned too, the Weygand Plan was dead.
Detailed plans to implement the above order for withdrawal northwards were agreed in the following terms, ‘subject to no deterioration on Belgian front’. British orders were issued accordingly.
1. Night of 26th/27th May
The French:
Rear-guards on the Scarpe; main body on the line Pont à Vendin–Thumeries–Pont à Marcq–Bourghelles.
The British:
Rear-guards on the frontier position; main body on the line Sainghin–Annapes–Marcq–Warneton.
2. Night of 27th/28th May
The French:
Rear-guards on the Deule; main body on the Lys.
The British:
Departure of rear-guards from the frontier position at midnight on 27th to occupy the line Warneton–Wambrechies–the Deule at Lille; main body on the Lys.
The forces holding the La Bassée Canal to Robecq remain in position during these two nights.
3. Night 28th/29th May
French and British:
Withdrawal of rear-guards on to the Lys and of the forces holding the La Bassée Canal to Robecq.(6)
It should be observed that both in General Blanchard’s order and in the agreement implementing it, only withdrawal to the Lys was provided for. There was no discussion of any further withdrawal, and General Blanchard’s report to General Weygand read:
… British Expeditionary Force, First Army and Belgians will withdraw to line Aa–Lys–Canal de Dérivation from which there will be no further retirement. First Army will withdraw to line Scarpe night 26th. Belgians supported by French mechanised division will reduce pocket at Courtrai. Admiral Nord will act against enemy west of Aa.(7)
On returning to his Command Post Lord Gort found a personal message from Mr Eden:
I have had information all of which goes to show that French offensive from Somme cannot be made in sufficient strength to hold any prospect of junction with your armies in the north. Should this prove to be the case you will be faced with a situation in which safety of BEF will be predominant consideration. In such conditions only course open to you may be to fight your way back to west where all beaches and ports east of Gravelines will be used for embarkation. Navy would provide fleet of ships and small boats and RAF would give full support. As withdrawal may have to begin very early preliminary plans should be urgently prepared. You should also
consider urgently security of Ostend and Dunkirk to which latter port Canadian Bde group is being sent night 26th/27th. Prime Minister is seeing M. Reynaud tomorrow afternoon when whole situation will be clarified … (8)
This was followed by another message to say that the Canadian Brigade would not be sent.(9)
Lord Gort reported in turn to the Secretary of State that plans for a withdrawal northwards had that morning been agreed with the French, but that news from the Belgian front was disquieting. He concluded ‘I must not conceal from you that a great part of the BEF and its equipment will inevitably be lost.’(10)
Another message came from Mr Eden:
Prime Minister has had conversation with M. Reynaud this afternoon. Latter fully explained to him the situation and resources French Army. It is clear from this that it will not be possible for French to deliver attack in the south in sufficient strength to enable them to effect junction with northern armies. In these circumstances no course open to you but to fall back upon the coast in accordance terms my telegram … M. Reynaud communicating General Weygand and latter will no doubt issue orders in this sense forthwith in conjunction with French and Belgian Armies.(11)
The policy of evacuation seemed thus to have been accepted on the highest political level. Moreover, the Howard-Vyse Mission at French Headquarters informed the War Office that after receiving a copy of General Blanchard’s order for withdrawal, quoted above, General Weygand had ‘consequently sent for Admiral Darlan to study re-embarkation’.(12) Unfortunately, inability to take a prompt decision and to give clear orders again resulted in misunderstanding, for neither General Blanchard nor the Admiral in charge of the Dunkirk area was told by the French High Command that evacuation was intended. General Blanchard was left to believe that a final stand was to be made on the Lys and so he failed to realise the need, much less the urgency, to plan any further withdrawal.
Lord Gort suffered from no such handicap. A week before he had been clear in his own mind that if the French failed to close the gap in their front he might be forced to retreat to the coast. The War Office and the Admiralty had been led to realise this too, and had been preparing for such a possible contingency. And now that the attempt to close the gap was abandoned the Government saw that the contingency had become a reality. At once, they told Lord Gort: ‘You are now authorised to operate towards cost forthwith’(13) and at the same time they told the French Government that the policy must therefore be to evacuate and orders to this effect had been given to
Lord Gort. There was no ambiguity here, nor any room for misunderstanding of British intentions. Had the French High Command made known the decision to French commanders in the field with equal promptitude and clarity, much subsequent trouble would have been avoided.
With the cancellation of the Weygand Plan, III Corps were free to resume command of the forces on the western front. General Adam was however appointed to organise the Dunkirk bridgehead, and Major-General S. R. Wason (who had been Major-General Royal Artillery at General Headquarters) was appointed command III Corps.(14) He spent much of the next two days trying to coordinate plans for the withdrawal with the French commander on his left. In this he had great difficulty owing to the breakdown of communications, the frequent moves of headquarters and the growing congestion of the roads; he did not in fact succeeded in gaining personal touch with his own divisions till the latter finally reached the Dunkirk bridgehead shortly before they were evacuated.
Meanwhile the divisions which were to come under his command had had an anxious day, for the German order forbidding resumption of the advance had not prevented the enemy from continuing his efforts to enlarge bridgeheads across the Canal Line.
The northern sector, now thinly held by French troops, was still on the Canal Line from Gravelines to St Momelin, though the enemy had a bridgehead near St Pierre Brouck. The main British defence on this flank was now forming farther east on a front reaching from Bergues through Soex, Wormhoudly, Cassel and Hazebrouck. Here the 48th, 44th and part of the 46th Divisions were now in position, though Cassel and other places were shelled and bombed they were not attack on this 26th of May. On the front of the 2nd Division, however, where the enemy already had a bridgehead east of Aire, the 2nd Division had to fight their way forward in an effort to reoccupy the Canal Line. They advance to within a mile of the canal but they were then held up. Fighting went on here all day, and the left flank battalion of the 6th Brigade the 1st Royal Welch Fusiliers—was gradually forced to fall back on the 2nd Durham Light Infantry in St Venant with heavy loss, leaving one company in Robecq, surrounded and reduced by casualties to a small party. Meanwhile enemy tanks and infantry passed between Robecq and St Venant to attack Merville. They made repeated attempts to capture the southern bridge leading into the town, but the 6th King’s Own (a pioneer battalion) with the help of a single field gun defeated all their efforts, captured twenty prisoners, and destroyed two armoured cars and three tanks.(15) During the night the garrison was reinforced by a troop of the 10th Field Regiment and two guns of the 115th Army Field Regiment.
On the rest of the 2nd Division’s front there were strong attacks through Bois de Pacqueaut and in the Béthune salient. The 4th Brigade finally held the enemy at the northern edge of the Bois de Pacqueaut and the 5th Brigade stopped his advance towards Estaires. But here, behind Béthune, he won a small bridgehead, and there were sign that he was massing for a more formidable effort to break through.(16) It was in fact the opening of a battle in which the 2nd Division was to fight to a finish while the first moves of the general withdrawal took place behind them.
On the left of the 2nd Division, about four miles east of La Bassée, the enemy attacked near Bauvin, where the La Bassée Canal joins the Haute Deule Canal before the latter makes a right-angle bend through Pont à Vendin to Oignies. At Oignies too the enemy attacked. The 139th Brigade of the 46h Division held the salient, interspersed with troops of two French divisions who, as withdrawal progressed, were to take over the line to La Bassée. By ten-thirty in the morning forward posts had been overrun and the enemy had reached a line facing Provin, Carvin and Oignies. The 151st Brigade of the 50th Division, which had been withdrawn to the area south of Lille when Arras was given up and had not been moved to the Ypres front, came to the assistance of the troops attacked, and a line across the salient was established. Carvin was in enemy hands at one time but was retaken by counter-attack.(17)
In this southern sector the enemy were trying to link up with units of Army Group B attacking towards Seclin from the east. The embargo which kept the German divisions facing the canal line further north did not apply here, or where the French First Army stood between the two British fronts. The French were heavily attacked during the day but held out, and the enemy’s efforts to break through both British and French sectors were defeated.
British divisions in the old Frontier Line were not seriously attacked though they were subjected to heavy shellings. From our forward positions considerable bodies of enemy troops were seen in the distance moving northwards across out front, but by now it was essential to husband carefully the very meagre supplies of ammunition which remained and the artillery were forced to let them pass unmolested. Yet the position on our left grew hourly more threatening as Belgian withdrawals under heavy attack widened the gap between our left and their right. It was now known that they would not withdraw westwards to continue the Allied front, for Lord Gort had received through the Belgian Mission at his Headquarters a note from General Michiels, the Belgian Chief of Staff, containing the following passage:
Today, 26th May, the Belgian Army is being attacked with extreme violence on the front Menin–Nevele, and since the battle is now
spreading to the whole area south of Eecloo, the lack of Belgian reserves makes it impossible to extend our boundaries, which were notified yesterday, further to the right.
We must therefore, with regret, say that we have no longer any forces available to fill the gap in the direction of Ypres.
As regards the withdrawal to the Yser the idea must be ruled out since it would destroy our fighting units more quickly than the battle now in progress, and this without loss to the enemy.(18)
Lord Gort also received a number of messages from the British Mission at Belgian Headquarters from Sir Roger Keyes in the same sense but also appealing urgently, on the Belgian behalf, for additional air cover and a British counter-attack at this threatened point of the Belgian front. ‘If enemy is not driven back in Courtrai salient the whole front may collapse.’(19) But a British counter-attack here was out of the question, for the only British units not already engaged were being hurried northwards to close the gap. The 5th Division found the position they were to occupy south of Ypres already under German shell-fire when they arrived and, indeed, they only just managed to be there before the enemy. General Brooke spent a hectic day collecting troops and artillery with which to extend his front northwards and had certainly neither troops nor ammunition for counter-attack elsewhere. The 12th Lancers operating on the flank had found Ypres undefended with its bridges unblown; and the nearest Belgian troops they could located were at Zonnebeke eight miles away to the east.(20)
The situation on this evening is shown on the situation map at the end of this chapter.
The Royal Air Force too could do but little for the Belgians in view of their other commitments. During the morning three reconnaissance sorties were sent to the area of German pressure on the Belgian front and all failed to return. But at eight o’clock in the morning, on reports received from the Air Mission at Belgian Headquarters, eighteen bombers under fighter protection attacked enemy troops and transports approaching the Lys crossings on either side of Courtrai as well as bridges and roads. They also bombed a number of airfields about St Pol which the enemy was reported to be using.(21)
On this evening the opening moves were made in the withdrawal of the British Expeditionary Force to the Lys. Eventually they were to lead to Dunkirk.
Dunkirk is an ancient seaport which has figured many times in military history. The remains of Vauban’s fortifications are still traceable, though less well preserved than those of Gravelines on the west. East of the town the coast which was to be included in the
Allies’ bridgehead stretches away to Belgium, eight miles off, and from there to Nieuport, nine and a half miles farther still. For the whole seventeen and a half miles the shore is a wide belt of shelving sand. At Malo les Bains, Bray Dunes and La Panne there are long sea-walls or parades of brick for the convenience of their summer visitors. Behind, between and beyond these resorts, lie undulating sand dunes—mile after mile of them—half clothed with long sharp grass and patches of sea thistle. To landward of the dunes is, first, a mile-wide strip of common and scrub, and thereafter meadow land intersected by a number of canals (chief of which is a broad canal running direct from Dunkirk to Furnes not far behind the sand dunes) and by numberless smaller waterways for the drainage of the low-lying flood-threatened land. (See map facing page 238.)
Six miles south-east of Dunkirk stands the old fortified town of Bergues. The Bergues Canal, which joins the two, formed a western boundary to the British sector of the perimeter, for the French were to hold the sector west of this line. From Bergues, the Bergues–Furnes Canal winds its way to Furnes, yet another of the towns which Vauban fortified, fourteen and a half miles from Bergues and four from the sea coast at La Panne; and then to Nieuport, six and a half miles further east and only two miles from the coast. This canal line formed a southern boundary to the bridgehead; the whole perimeter to be held extended for about thirty miles. It is a fairly strong defensive position. Much of the land inside the canal-marked boundary is easily flooded, and outside it, for many miles, the ground is of the same low-lying, much-beditched sort; it is almost impassable by tanks or guns except on built-up conspicuous roads, with ditches either side, which a few well-sited guns could make unusable. (Four years later we were to find that very similar country in ‘the Island’ between Nijmegen and Arnhem was impassable by our armoured divisions so long as the enemy’s guns covered the causeway roads.)
It may be well to review what had happened in the Dunkirk bridgehead before the Government’s decision to attempt full evacuation was reached. As already told, it was as far back as May the 19th when Lord Gort first reported to the War Office that retreat to Dunkirk might become inevitable. Inter-departmental consultations which eventually resulted in the Admiralty plan ‘Dynamo’ began next day. At the same time Lord Gort’s Adjutant-General was instructed to get rid of all ‘useless mouths’, an uncomplimentary but expressive term for those whose service would no longer be needed by the constricted fighting forces in France.(22) On the following day Colonel G. H. P. Whitfield, Assistant Adjutant-General, was ordered to take command of British non-fighting troops in the Dunkirk area and to start evacuating those no longer required, at his discretion and
as the situation permitted. There were many who could be spared from the floating population of men who when hostilities began had been going on leave or returning, who had been attending a course of training, had been attending a course of training, had been out of the line for rest or convalescence or, for on reason or another, were in the back area temporarily; and from those who had been permanently employed there as staffs of training establishments, reinforcement centres, or supply depots, or in a variety of duties on the long lines of communication. Finally there were the further large numbers who had been engaged on the making of airfields or on other constructional tasks. All this activity would inevitably be found behind an army in the field for which a large expansion was being prepared. A considerable proportion of these men had been specially enlisted for the work they were engaged on: they were neither trained as soldiers nor equipped for fighting. They were now not an asset but a liability and the sooner they were got away the better. In addition many of the fighting units, when ordered at short notice to advance to the Dyle, had left behind dumps of their surplus stores in charge of small rear parties who still further swelled the total number in rearward areas. When the German armoured divisions broke through the French front to our right, cut British communications at Amiens and Abbeville and swirled northwards, all these men, dispersed throughout the back areas, were caught between our retiring army and the tide of enemy forces pressing northwards to the coast. There was neither time nor the necessary transport to collect and move them all on any carefully worked out plan. All that could be done in such an emergency was to order them to make their way north, first to the line Orchies–Lens–Frévent (and this order was given on the 17th) and later to the Dunkirk bridgehead. Some, as has been told, were organised as fighting units in one or other of the special ‘forces’ or formations (Macforce, Polforce, Don Details, etc.). Some were evacuated from Boulogne or Calais before those places were lost; but most of them eventually found their way to the Dunkirk bridgehead in larger or smaller parties. Following the general order to withdraw, many had made their way through enemy-infested country without trained officers or detailed orders to guide them, and if the unsoldierly appearance of some parties shocked better-trained soldiers who witnessed their arrival, the fact that they arrived at all was, in reality, more remarkable evidence of untutored initiative and a dogged determination to avoid capture—which is at least one mark of a good soldier.
On May the 23rd Colonel C. M. Usher had been order to take charge of this movement and in particular to sort out fighting troops who could be used for the defence of the Canal Line and the Dunkirk bridgehead till the divisions from the east arrived to take it over.(25)
From some of these he had formed ‘Usherforce’ (page 123), which, with the French troops there, held Bergues and screened Dunkirk until more solid defence could be organised.
An order from the War Office had been received on May the 24th laying down the policy of partial evacuation as they envisaged it at that date. They then held it to be essential to retain in France ( a) all personnel who might possibly be of value for working the port, unloading supplies, and getting them forward, and (b) all fighting personnel.(24) But on the same day more heavy German bombing badly damaged the dock area of Dunkirk and caused much run in the town. The main water supply was cut and never functioned again. It looked as though evacuation from Dunkirk might soon became impracticable, and other possibilities were studied. Meanwhile the anti-aircraft defence was strengthened. Major-General H. G. Martin, Major-General Anti-Aircraft Artillery on General Headquarters Staff, assumed command; the 2nd Anti-Aircraft Brigade took command of all anti-aircraft artillery in the area, and the 5th Searchlight Brigade of all searchlight units.(25)
By May the 25th the 48th Division had arrived on the western flank and Usherforce, in Bergues, came under General Thorne’s command. And when on the 26th the policy of complete evacuation (in so far as that was possible) had been accepted by the Government and Lord Gort had been informed, Lieutenant-General Sir Ronald Adam was appointed to take command of British troops in the Dunkirk bridgehead and to arrange in conjunction with the naval authorities for the evacuation of troops to England. Sir Ronald Adam was to have had with him Lord Gort’s Adjutant-General, but the latter had moved to Dover with Rear General Headquarters which left via Boulogne on May the 23rd. Instead he was assisted by Lieutenant-General Lindsell, Quartermaster-General, Major-General R. P. Pakenham-Walsh, Chief Engineer, with Lieutenant-Colonel the Viscount Bridgeman as General Staff Officer.
The first task was to organise the defence of the perimeter. For this, General Thorne lent Brigadier the Hon E. F. Lawson, commanding Royal Artillery, 48th Division, who proceeded to assemble and post the troops already available or arriving in the bridgehead.(27) The second task was to organise the bridgehead for the reception, and later the evacuation, of the retiring divisions. It was divided into three Corps Areas, each with a collecting area outside the perimeter, a sector of the perimeter to defend, and a sector of the beach for evacuation. II Corps was allotted the eastern sector, I Corps the central sector, and III Corps the western sector nearest to Dunkirk. In each sector dumps of rations and ammunition were established.
The third problem was traffic. As troops and their transport began to arrive in increasing numbers from all three corps it became
apparent that the order to disable and abandon their vehicles outside the perimeter had not always reached them. For this reason, and because the number of men available for traffic control was not at first adequate, large numbers of vehicles were entering Dunkirk and the bridgehead at this time. In the congested state or roads, vehicles were liable to be separated from their units during the withdrawal and units from their formations. Such detachments, arriving without clear orders, were sorted out and sent to reinforce the defence or to the coast for evacuation as seemed best to those in control. Thus by the 26th the organisation and defence of the bridgehead was already taking shape when an instruction that, ‘as withdrawal may have to begin very early preliminary plans should be urgently prepared’ was received from the Secretary of State for War.(28)
From now on all three Services faced their most difficult and dangerous tasks. The Army still had to fight its way back to the coast, facing both ways as the enemy attacked from east and from the west, and with the knowledge that Belgian resistance was nearing its breaking point. The Royal Navy had to conduct a most complicated and hazardous operation in which they must contend not only with inevitable risks of wind, weather and navigation in crowded and constricted waters, but must do so in the teeth of violent opposition, working always against time. And the Royal Air Force had to frustrate the Luftwaffe’s declared intention to make evacuation impossible.
In the evacuation of non-fighting troops already in progress the Navy had begun by using Boulogne, Calais, Dunkirk and Ostend, and by midnight on the 26th of May they had brought to England 27,936 men who were no longer needed in France.(29) At first it was hoped that if general evacuation became necessary the same ports could be used, but by May the 26th Boulogne and Calais were in enemy hands and, with Belgium likely to collapse, Ostend was no longer available. Dunkirk and the eastward beaches alone remained and enemy bombing threatened to make the continued use of Dunkirk harbour impracticable.
Almost continuous cover was provided by the Royal Air Force during the greater part of the day, patrols at squadron strength taking off from British airfields at approximately fifty-minute intervals from half past four in the morning till half past seven at night and intermittently till nearly dark. They had four contests with the enemy before nine o’clock in the morning and, shortly after, they fought a force estimated to consist of twenty-one bombers protected by thirty fighters which was attacking Dunkirk and the shipping off the coast. There were further combats in the afternoon, but in the evening fewer enemy aircraft were met. In all, about 200 sorties were flown. Six of our aircraft were lost, but the enemy’s air return for the day
shows that thirty-seven of their own machines were destroyed and seven damaged, most of them in the Dunkirk area. The Luftwaffe reported strong anti-aircraft defence behind the front and over the ports and fighter defence considerably stronger than on the previous day particularly near the coast. It was observed that fighter formations were exclusively British, operating from the other side of the channel.(30)
Yet while many of the enemy’s aircraft were thus engaged in battle with our fighters, others bombed and machine-gunned the port and shipping. The non-fighting troops evacuated during the week had been brought home by a few ships sailing at intervals. These had managed to war off or evade the Luftwaffe’s attacks, but full evacuation would require an offshore concentration of shipping which would be far more vulnerable. Vice-Admiral Sir Bertram H. Ramsay, Flag Officer Commanding Dover, had been appointed to plan and control evacuation if it should be ordered.(31) On Thursday the 23rd he informed all concerned that, if ordered , the operation would be known as ‘Dynamo’. His initial plans were well advanced when, on this Sunday evening, May the 26th, shortly before seven o’clock the Admiralty sent the signal which would influence the whole course of the war:
‘Operation Dynamo is to commence’.(32)
Situation on the evening of 26th may 1940