by Barbara Bond
Three British prisoners of war chat to a German officer in the Red Cross parcel store at Stalag Luft III (Sagan). Piles of Red Cross parcels can be seen stacked up behind them. MI9 scrupulously avoided using Red Cross parcels, acutely aware that absolutely nothing should impede the flow of such parcels into the camps or compromise the Red Cross.
The degree of contact with the camps varied enormously. Stalag VIIA (Moosburg), for example, did not apparently receive very much by way of escape aids. This camp was located some forty-seven kilometres (twenty-nine miles) northeast of Munich and by 1944 there were in excess of 10,500 British prisoners of war in the camp. After the war, one of the liberated prisoners reported that the only escape aids they had received were contained ‘in some gramophone records’ which arrived in July 1942 and no further parcels were received for the duration of the war. This clearly indicates that delivery was patchy to some of the camps.
The methods of communication, especially the coded letter traffic, between MI9 and the camps, played a very significant part in the whole story of the escape and evasion mapping programme and are, therefore, addressed in detail in the following chapter.
CAMP ORGANIZATION
Given the considerable level of organization, planning and activity which characterized the work of MI9 to support successful escapes, it arguably comes as no surprise to discover that this was matched by a similar level of organization and activity in the camps. Each camp sought to create its own Escape Committee, headed by the Senior British Officer (SBO), or the Senior American Officer (SAO) in camps where the two nationalities were mixed. All escape plans had to be authorized and overseen by this Committee. While the organization, of necessity, was rather more loose than that of any operational battalion or squadron, organized it most certainly was, albeit in a very unobtrusive way. In the Marlag and Milag Nord camp, the Escape Committee had a system of ‘patents’; all schemes were registered with the Committee and each person was allowed the first attempt with their own idea. The Escape Committee directed and supervised all activity in support of any plan it authorized, including the provision of the requisite escape aids. The aids provided by MI9 were carefully allocated, plans were monitored, and all supporting activity, such as the provision of civilian clothes, the forgery of local papers required for travel or the copying of maps, was overseen by the Committee.
It is likely that MI9 was helped in its attempts to hoodwink the Germans by the age, physical condition and lifestyle of the guards. Many of them were elderly and certainly not fit enough for operational action on the front lines. Their own lifestyle was far from comfortable, with the result that many were easily bribed. In some camps it is clear that the black market was extensive and the Germans were very corrupt, ‘there being nothing that could not be obtained at a price for either money or cigarettes,’ as James remarked. While some of the ruses and methods employed by MI9 were discovered and they had to keep coming up with new ones, it is clear that the sheer volume of activity by MI9 in keeping up the flow of escape aids helped to support many successful escapes.
Those prisoners who had particular expertise from their civilian employment were given support work which maximized the value of their contribution. Prisoners in the Brunswick camp, for example, created a crude, but very effective, print works to reproduce maps (see Chapter 8). John Pryor, whose personal story will be recounted in more detail in Chapter 7, was regarded as the master forger in Marlag and Milag Nord camp. His son recalls that his copperplate handwriting could look as if it had been typeset. Clearly an innate talent was put to good use during his captivity in producing forged passes for potential escapers, an artistic talent which he subsequently employed to good effect as a hydrographic surveyor when he returned to active duty after the war. Those who had been tailors were employed to make the civilian clothes; those with any kind of technical, or even criminal, bent were able to pick locks, make keys or even steal items which were needed. The men had sufficient leisure time to scrounge or steal from, or bribe their captors; any bribery was usually done with cigarettes.
A contemporary War Office map showing the location of all the prisoner of war camps in Germany.
(inset): Map detail of the area around Colditz.
It was usual, though by no means consistently done, for those planning to escape to be employed on map copying, as this afforded them the opportunity to learn the geography of the terrain over which they planned to travel. There is, however, little mention in the subsequent escape reports of the maps, which appears to reinforce Professor Foot’s comments in a conversation in 2012 that all who were issued with escape maps were briefed never to mention them: it is clear that few did. There is evidence that in some of the camps, roster systems and timetables were organized so that, as some of the men were deployed copying maps or producing forged documents, for example, others were deployed to act as lookouts and give warning of the approach of any of the German guards.
It is clear that there was a level of organization in many of the camps which allowed the escape activities to proceed relatively unencumbered. The infrastructure that was created allowed many of the escape plans to proceed to a successful outcome. It was very important in the greater scheme of things that the camp organizations were effective in realizing the benefits of MI9’s detailed work in support of escape activity.
VOLUME OF PARCELS DESPATCHED TO THE CAMPS
MI9 kept detailed records of the despatch of parcels to the camps. Almost certainly this would have been in the form of a card index noting the contents of the individual parcels, to which camps they were despatched, when and what acknowledgements were received. Although this record does not appear to have survived, it is possible to track the volume of the parcels despatched through the monthly entries in the War Diary. For example, the entry for August 1941 indicated that 497 had been despatched up to that point, of which 78 had been acknowledged. An additional 193 clothes parcels, i.e. straight parcels, had also been despatched, of which 33 had been acknowledged. By July 1943, almost 400 parcels were despatched in a single month to camps in Germany and Italy and one of the parcels sent to Germany consisted entirely of escape aids. No evidence has been found to support the hypothesis that the Germans had an equivalent organization and there appears to be no indication that there was any similar traffic passing in the opposite direction, although it is not possible to make an unequivocal statement to this effect.
The story which emerges from this chapter is one of breath-taking ingenuity and inventiveness engendered by necessity, initially by MI9, but the more so by the prisoners of war themselves. Having embarked on a programme to produce escape and evasion maps in an appropriate form and in sufficient numbers to ensure that the escape philosophy was enacted in reality, MI9 sought to ensure that those maps reached the camps in prompt and effective ways. Escape, whether ultimately successful or not, took a great deal of planning both at home and in the camps, and MI9 showed their acute awareness of this and the extent to which the maps were a key part of successful escape. It is also clear that the prisoners of war showed admirable courage and indefatigability, apparently accepting and actively responding to the philosophy of war that it was each man’s duty to attempt to escape. The Escape Committees must have been reassured in their commitment and endeavours when they saw the extent to which MI9 was seeking to support them. When they asked for items, MI9 did their best to respond. The escapes from the camps were always a team effort and for every man that made it home successfully, there was a support team left behind in the camps. Similarly, at home, there was a very real sense of teamwork and cooperation as commercial companies in the UK contributed both materially and in terms of their expertise to the whole escape and evasion enterprise which MI9 had created and fostered. It is certainly the case that the reality of what was done has proved to be decidedly more astonishing and impressive than that conveyed by any work of fiction.
5
CODED CORRESPONDENCE WITH THE CAMPS
‘Cryptography concern
s communications that are deliberately designed to keep secrets from an enemy.’
(The Code Book. The Secret History of Codes and Code Breaking by Simon Singh)
It is clear from the previous chapter that it was critical to the success of getting maps and other escape aids into the camps, in order to assist the prisoners of war in planning and executing their escape, that regular contact with them was established and maintained by MI9. Under the Geneva Convention, prisoners of war were allowed to receive up to two letters and four cards monthly. MI9 took full advantage of this aspect of the Convention by establishing a system of coded letter exchanges with the camps. This was certainly the principal method of contact before wireless sets were smuggled into the camps.
The sheer volume and real significance of the coded letter traffic has begun to emerge, especially as a result of the successful deciphering of a cache of Lieutenant John Pryor’s coded letters. Coded letters constituted a vital means for gathering intelligence from the prisoners of war and a channel through which they, in turn, could send their requests for escape and evasion maps of particular areas. The evidence assembled has thus substantially reinforced the significance of the coded letters which was highlighted in the author’s discussion with Professor M. R. D. Foot in January 2012. There can now be no doubt that coded letters were a key part of the system which ensured that maps and other escape aids reached the camps in a timely fashion to aid the escapers in their attempts to return home.
The letters allowed the potential escapers to indicate precisely what they needed to support their escape plans and, in turn, alerted them not only to the nature of parcels being sent but also to the particular markings they would carry. The coded letters were of crucial significance to the way in which MI9 was able to ensure that information on escape aids, not the least of which were the maps, was communicated with the camps. Requests for, and the despatch of, items to aid the escapes which prisoners were planning were made through this important and covert channel of communication. Discovering how it worked, why, and just what it owed to the sheer ingenuity and commitment of both MI9 and the prisoners of war themselves provides another key part of the whole story of the escape and evasion mapping programme.
MI9’S CODING SYSTEM
In his fascinating book on the history of code use, Simon Singh highlights the importance of effective coded communication through history by monarchs and generals in governing their countries or commanding their armies and the fact that it was the threat of enemy interception of critical messages which was the catalyst in the development of codes and ciphers.
Singh, in particular, describes how the practice of utilizing codes has often had a dramatic impact on the course of history. How different, for example, might British history have been had Mary, Queen of Scots, not engaged in treasonable activity and incriminated herself through coded letters. The letters were intercepted and successfully deciphered by Queen Elizabeth I’s Principal Secretary, Sir Francis Walsingham, generally acknowledged as the founder of Britain’s Secret Intelligence Service. The letters between Mary and Anthony Babington did use an elaborate and very obviously enciphered text, and it was from Tudor times onwards that the art of enciphering and coding grew inexorably. To be strictly accurate, the word ‘cipher’ should be used in the context of MI9’s system since it more appropriately describes the cryptographic process of hiding or disguising secret messages. Codes use words to disguise, for example, the identity of an agent or the nature of an operation: Airey Neave’s codename in MI9 was Saturday and Overlord was the codename for the Allies’ invasion of mainland Europe. However, the terms ‘code’ and ‘coded’ are used here as they are most commonly used and understood by laymen.
The system which MI9 elected to pursue, however, was, of necessity, rather different to the obvious encipher approach which would never have made it past the German censors. MI9 chose rather to develop a system of constructing letters which would not arouse suspicion by appearing quite innocuous, yet containing a hidden message. This was a distinctly alternative way of employing cipher alphabets. In essence, it did not matter if the general encryption method, or algorithm, became known; rather it was the specific key which identified the particular encryption which needed to remain secret. Even if the encoded message or cipher text was intercepted by the enemy, it could only be deciphered if the key was known. This was exemplified exactly in the deciphering of John Pryor’s letters.
The general encryption method which MI9 employed has been known for some time since it had been publicized originally by Julius Green and later by Foot and Langley. The key comprised two Arabic numbers and an alphabet letter. In Green’s case this was 5 6 O, and he showed how the code worked in his book, From Colditz in Code, published in 1971. The book was based entirely on his personal experiences as a dentist in the field during World War II and specifically as a prisoner of war, eventually in Colditz. Green had been a Territorial Army reservist from his days at Edinburgh University in the early 1930s. He was commissioned in 152 Field Ambulance Brigade of the 51st Highland Division on 24 August 1939.
Julius Green, a code user in Marlag and Milag Nord and Colditz camps, working as a camp dentist.
However, Pryor’s individual key was not known and had to be identified in the course of this study. The numerical parts of his code were discovered early in the research as he had recalled it in his memoirs as 5 4, correctly, as it later transpired, but he had not recorded the alphabet letter. The discovery of the key was achieved by a lengthy process of elimination, testing each letter of the alphabet until a word which made sense was deciphered. This proved to be the letter S. Professor David McMullan, of the School of Mathematics and Physics at Plymouth University, provided considerable assistance in identifying the full key for John Pryor’s code which enabled the deciphering of his letters. This greatly contributed to a more detailed understanding of the importance which the system of coded correspondence played in MI9’s escape and evasion mapping programme. A full consideration of the construction of the code used in the letters is given later in this chapter.
SELECTION AND TRAINING OF THE CODE USERS
It is not surprising that coded correspondence between MI9 and the camps played such a key role in the escape and evasion mapping programme. One of the intelligence organizations that pushed hard for the creation of MI9 in 1939 was MI1. MI1 was the Military Intelligence Code and Cipher School which subsequently morphed into the Government Communications Headquarters, more generally known as GCHQ. It is, therefore, quite likely that MI9 staff also worked with MI1 in the development of the coded communication with the camps, although no confirmation of this likely connection has yet been discovered.
With the fall of France in June 1940, barely six months after the creation of the Branch, MI9 knew that over 50,000 Army personnel were in captivity and very few of them had been briefed on any aspect of escape and evasion, and none on coded correspondence. Indeed, at that stage they knew of only three prisoners of war who were code users, two in the Royal Air Force and one in the Royal Navy. They very quickly alerted the censors to the need to try to identify any letters from prisoners of war which they ‘suspected of secondary meaning or of containing a private means of communication’. Through this means they were able to identify a few private codes which some individuals had had the foresight to establish with their families prior to deployment. MI9 contacted these individuals, initially using the private codes they had set up.
By early 1941, MI9 was in contact with men who had been briefed on the coded system prior to deployment and who were in turn briefing others in the oflags into the system. The big challenge was then to establish contact with the stalags. They managed this through padres, doctors and dentists who had the opportunity to minister to the needs of the other ranks in the stalags and could identify those most likely to be able to pick up the coded system and use it. They then briefed these men and slowly the system was spread through the camps. During 1941 the work grew to such an extent that a de
dicated section had to be formed to cope with the increasing volume of coded letters being sent and received. The new section, Section Y, was formed in January 1942 and was attached to the Training School in Highgate. From these small beginnings, the coded system of contact with the camps grew and developed apace.
Potential coded letter writers were initially selected by the MI9 lecturers and trainers from officers who attended the training courses at the Training School or who they met during their lecturing visits to the various RAF camps and operational Army units. MI9 was on the lookout for men who appeared bright, responsible and discreet. These individuals were taken aside at the end of the lecture or training course and taught a simple code so that, if captured, they could conceal a coded message in an apparently routine letter to their family. Before the selected individuals were authorized as code users, they were required to do practice exercises to ensure that they were proficient enough with the system of encoding.
Naval prisoners of war at Marlag and Milag Nord, 1941. Julius Green is first left in the front row.
By September 1940 coded letters were being exchanged with men in prisoner of war camps in Germany and, at home, a scheme had been started to ensure that contact was maintained with the close family of any code user who had been captured. Local intermediaries were established on a regional basis and families were regularly briefed. MI9 was determined that their relationship with the families should be personal rather than being perceived as formal and official. The War Diary entry for August 1941 mentions the ‘good relations and close co-operation’ which had been established with the relatives and the extent to which it was increasing. Relatives clearly appreciated this and were known to have expressed their thanks to the War Office, indicating how they valued ‘the War Office keeping in touch with them in a personal way’ and not just behaving as an ‘official machine’. It must have been some consolation to the families to know that their sons were still doing their duty and continuing to contribute to the war effort whilst remaining in captivity. A letter headed MOST SECRET from MI9 on 16 December 1942 to Julius Green’s mother told her that:
