Introduction:

Poland had not existed as an independent political entity since 1795 when the Partition Wars between Russia and Austria carved up territory through the Congress of Vienna in 1815. There were no permanent military institutions or military traditions from which Poland could draw upon since their Prussian, Russian and Austrian masters had very different approaches and philosophies to military standing and planning. Poles had long dreamed, schemed, and plotted for the re-emergence of their independent country (Davies, 2001; Kochanski, 2012). Networks of underground organisations existed within military circles with former Austro-Hungarian officers leading the re-emergence of Poland’s military and government apparatus.

Poland had a long history with its connections to Scandinavia through conflict, trade (Olsson, 1988) and, not always an agreeable one. There is a need to understand past conflicts within Scandinavia to understand their foreign and diplomatic policies and ties prior to the outbreak of war in 1939.

In 1655 the Swedish king Charles X Gustav declared war on Poland after John II Casmir Vasa refused to concede Swedish aggrandisement through acquisition of Baltic states and the subsequent war is often referred to the First Northern War. The invasion was swift with Sweden using its alliance with the Brandenburg army and defeated the larger Polish-Lithuanian Commonwealth army just outside Warsaw. It was not until the peace treaty of Copenhagen in June 1660 that conflict appeared to be settled, despite Sweden not achieving its goals (Makiłła, 2016).

This was not the first time the two sides had fought each other as earlier wars over claims to the Swedish throne between 1600 to 1629 and again in 1635. Unfortunately, this did not settle Swedish-Polish affairs. Augustus II (aka the Strong) violently seized the Polish crown amid a conspiratorial alliance between the church and the powerful Sapieha family who were wealthy landowners whose political ties were with Russia and Austria. Augustus II saw an opportunity to strengthen his position and the Commonwealth through the invasion of Livland (Latvia) and restore eastern territories. Sweden would only offer peace on the abdication of Augustus that would enable Charles XII to strengthen Poland as an independent state and allied to Sweden. A state of war emerged in 1701 and lasted until 1706 (the Great North War) with Poland’s boundaries at the centre of the conflict against the Russian Empire whose allies were the Denmark-Norway union, Saxony, and the Polish-Lithuanian Commonwealth. With the election of Stanisław I Leszczyński as king of Poland in 1704, Augustus II claim to the throne waned and peace with Sweden resulted in the Treaty of Warsaw. However, Sweden’s ambitions were not settled and war with Saxony and Russia continued for another two years and galvanised Charles XII as a military genius that exposed him to becoming embroiled in the Spanish War of Succession. After 1660, a political scene was established in Europe despite some minor and major conflicts and remained the political shape of Europe until end of the 18th century (Makiłła, 2016).

Sweden’s foreign policy had its roots based on internal politics of non-aggression and avoided any alliance that would pressure them into joining conflicts (Tingsten, 1959) since 1814. This resulted in avoiding support for a pan-Scandinavian movement when Prussia and Austria invaded her neighbour, Denmark in 1864. The dissolution of the union with Norway in 1905 began a potential isolation that only war would reverse at the outbreak of Great War and again resisted pressure to join Germany to reclaim Finland. Under the League of Nations decision in 1921, the contested Aaland Islands remained Finnish and at the time caused little impression on Swedish public opinion despite their military significance and sovereignty where the population was dominantly Swedish (Padelford and Gösta A. Andersson, 1939). Only when Poland’s claim to Vilnius drew the attention to Sweden’s politicians and diplomats in 1923 and later in 1935 that Sweden vetoed Poland’s election to the League of Nations who complained of Sweden’s pro-German policies (Jaworski, 2015).

Having restored Poland’s independence in 1918, the Swedes were wary of their new neighbour and both sides lacked motivation or saw any strategic need for a political or economic alliance (Jaworski, 2019) despite some two thousand Poles living in Sweden prior to the outbreak of war (Kłonczyński, 2016). Common commercial interests had been developed in the mid-1920s and crystallized in 1934 when Sweden recognized Poland needed to balance its foreign policy with an alliance with France to counteract the posturing of the Reich and Soviet Russia through developing trade and cultural activities with Sweden (Jaworski, 2019). At the outbreak of the war, Sweden admired the stance over Gdańsk (Danzig) and was open to supporting Poland’s resistance to the Reich’s demands as they became more forceful and threatening. On 13th August 1939, a meeting between the Nordic States reaffirmed Sweden’s neutrality as the outbreak of war drew closer and the Molotov-Ribbentrop Pact signed on 23rd August 1939 took Sweden by surprise but failed to being dragged into the war (Jaworski, 2019). Poland assumed Sweden would maintain a Polish-friendly neutrality. After war broke out the Swedish envoy, Joen Lagerberg proposed to Deputy Minister Jan Szembek a telegraph communications system via Sweden would be in place and that Polish diplomats in Germany would be handled by the Swedish embassy in Berlin. Sweden declared it neutrality in September 1939 and juggled its relationships with the Reich, the Soviets, and the Allies by maintaining trade, transport of Germany’s troops across Swedish soil through a transit agreement and even escorted German convoys in the Baltic. In effect, Stockholm became a ‘Nordic Casablanca’ (Lundberg, 2016).

Denmark’s foreign policy was shaped by the complex conflict of Schleswig-Holstein disputed concession to Denmark in a quarrel with the German Confederation in 1864. The two duchies had been ruled periodically by the Danish throne and given some autonomy that resulted in the duchies seeking membership of the German Confederation as a single state. Revolution and conflict enabled the Prussian Army to invade Denmark with a truce successfully negotiated at Malmö in 1849. Once the truce expired, the Prussian Army advanced into Denmark to the consternation of Russia, France and Britain that finally resulted in the Treaty of Berlin on 2nd July 1850 and later the Treaty of London on 8th May 1852 to give recognition to Denmark’s sovereignty over the duchies and restore the ‘balance of power’ in Europe. The dispute remained a ‘festering diplomatic issue’ that enabled Otto von Bismarck to challenge the status of the duchies again as a common Scandinavian front against the German Confederation emerged. Denmark’s stance on the German Confederation’s threats was taken too lightly due to the treaties covering the disputed duchies and the process of succession where Prince Frederick of Augustenburg whose popularity within Germany and Austria enhanced his claim to the duchies. The re-emergence of an Austrian-Prussian Confederation and the refusal to observe the legitimacy of the Treaty of London ensured another occupation and war was inevitable. War broke out with the invasion of Schleswig on 1st February 1864 and drew in a wider European interest, particularly Napoleon III. A settlement was a diplomatic mess and short lived with Austria rejecting Bismarck’s stipulation the duchies would be militarily subordinated to Prussia and settled for Holstein while Schleswig ceded to Prussia. After the Seven Weeks War between Austria and Prussia, the Peace of Prague on 23rd August 1866 saw the duchies ceded to Prussia and the emergence of the German Empire. After the Great War, the Paris Peace Conference in its attempt to settle long-standing sovereignty disputes decreed a plebiscite should be held. In 1920 the northern part of Schleswig to the northern bank of Flensburg Fjord became part of Denmark.

The Reich would on 9th April 1940 (Operation WESSERÜBUNG-SUD) occupy Denmark as a ‘steppingstone’ to Norway and despite its neutrality Denmark capitulated after a few hours of resistance thus becoming a ‘protectorate’ until 29th August 1943. Often described as a ‘mild’ occupation (Andersen, 2016) or nonviolent resistance (Sørensen, 2017), Denmark did have an active resistance through SOE. Members of the National Socialist Party (Danish Nazis) and recruitment into the Free Corps Denmark and the Waffen-SS from pro-German southern Denmark (Djursaa, 1980) indicated earlier conflicts had not settled the political orientation of the duchies.

As the outbreak of war became more likely, the Poles focused on strengthening its ties with Britain and France, rather than looking to Scandinavia for support despite these countries being geographically nearer to the Reich and Soviet Russia. The Scandinavian scenario for Polish diplomatic and intelligence gathering was not prioritized, leaving a ‘gap’ in the overall strategy until the mid 1940s. While Polish intelligence made significant contributions to both SIGINT (Link: Enigma) and HUMINT (Link: Polish Intelligence). Polish intelligence had also penetrated two agents into Oberkommando der Wehrmacht (Warlock) and the Oberkommando des Heeres (Knopf) provided key insights into German strategic and operational thinking during critical stages of the war (Winter, 2011) making it one of the most effective intelligence agencies during the war. Polish intelligence also had agents in Königsberg (Daskiewicz aka ‘Perz’) and in Berlin (Capt. Alfons Jakubaniec aka Kuba, Kuncewicz) who was arrested in mid-July 1941 (Pepłoński, 2005; McKay, 2020). Capt. Jakubaniec had prior to the Berlin posting, set up cells in Lithuania, Latvia, and Estonia (Pepłoński, 2005). These cells provided intelligence on airfield construction in Denmark and construction of U-Boats in Bremerhaven to Jarosłwa Pieniężny (Schwarz) also based in legation in Malmö (Pepłoński, 2005).

After the strategic muddle at Narvik in 1940 and the squabbling between SOE and SIS over the role and effectiveness of sabotage operations (Foot, 1990; Insall, 2021), Norway restricted Polish intelligence gathering mainly due to a lack of a Polish community other than POWs and Todt labourers (Kruszewski, 2016) and only responded to counterintelligence issues especially after the massacre at Telavåg in 1942 where the entire village was murdered in response to harbouring British spies. The Polish Government in Exile in 1940 broke contacts with Norwegian intelligence because of Britain’s strategic planning and began to focus on communication lines from 1941 onwards for its Scandinavian operations (Kruszewski, 2016). However, interned Polish naval personnel in Sweden were intercepting German radio traffic from bases in Norway and the Baltic states until the Swedish authorities intervened in the middle of 1943 (McKay, 2020).

Denmark:

About 12,000 Poles lived in Denmark at the outbreak of the 2nd World War where the Polish community had been established over 130 years (Śmigielski, 2022; Bułhak, 2023) whose roots lay in agriculture and industrial factories. ‘Continental Action’ would focus on civilian networks working for II Bureau and in the case of Denmark and Sweden, the quality of military intelligence was good throughout the war (Pepłoński, 2005). Polish Intelligence through II Bureau and activities of SOE’s Polish Section (E/ UP) would shape the strategic collection of military intelligence during the war in Denmark. The success of the Danish networks has been put down to SOASINT (Socially Assisted Intelligence) by Bułhak (2005) who suggests the ‘irregulars’ came from different strata of society and were able to fill the gaps in the ranks and operational intelligence service, particularly women whose role was key to its success.

From 1943 to their deaths in 1945, Anna Louise (Lone) and Lucjan Masłocha worked under the code name FELICJA JEDEN as part of the FELICJA organisation which provided domestic, international land and sea transport making ideal for networks within Scandinavia (Pepłoński, 2005). Lone, a Danish photographer met naval officer Lt. Lucjan Masłocha, a Polish agent while she was working for the Danish resistance Holger Danske through her connections to CRITRONEN (Jørgen Haagen Schmidt), a notable saboteur, rescuer, and assassin. Lucjan had escaped from a POW camp XIC near Lübeck and was trained in Sweden in 1943 for underground operations and reported directly to Adam Sokólski who ran FELICJA in Denmark. Sokólski was a teacher and Scout leader which gave him a suitable cover for the ‘Continental Action’ operations.

The intelligence gathered through FELICJA passed from eight cells functioning in Copenhagen and larger cities (Nivå, Helsingør, Nykøbing, Maribo, Nakskov and Haderslev) to Bolesław Rediger who was based in the Polish Consulate in Malmö (Pepłoński, 2005) who was then succeeded by Romana Heinzówna (Kruszewski, 2016). Lone and Lucjan Masłocha were betrayed and caught by the Gestapo in a villa which housed a W/T set. Lone was killed and Lucjan taken to the Gestapo HQ in Copenhagen and tortured to death. Sokólski’s cover was later blown and escaped to Sweden where he learned the Gestapo in Gdańsk were seeking his extradition.

Relations with the Danish intelligence were strained due to the exertion and influence by SIS and for an apparent reason that the Danes suspected the Poles were pro-German operatives (Bennett, 2005). Although SIS had passed the main intelligence gathering to SOE (Bennett, 2005) the relationships between the various agencies remained strained throughout most of the war. Cell 2 set up ‘Lupus’ and ‘Wolf’ but was short lived and cell 4 under Lt. Masłocha (Pasek) failed to develop its effectiveness (Bennett, 2005) with SIS reporting many cells had closed or had limited execution due to shipping restrictions in the Baltic which impeded flow of intelligence and agents or materials. Bennett (2005) also pointed towards hostility by the Danish underground which seems to contradict Bułhak’s (2005) and Kruszewski’s (2016) analysis. However, there is some evidence to suggest that II Bureau also curtailed co-operation with the Danes based on the need to limit contacts and minimise the networks exposure to counterintelligence operations through maintaining secure ‘lines’ from Poland into Denmark and Sweden (Kruszewski, 2016). The Polish community was largely made up of agricultural and factory workers where courage and determination more than made up for other skills needed for underground work (Kruszewski, 2016) and was not necessarily a limiting factor in operations.

By the end of 1941, the operation had 30 agents and couriers drawn from the ex-pat Poles, Danes, Kriegsmarine, and Wehrmacht soldiers with a further 150 supporting the cause, (Pepłoński, 2005) using their own codes and provided valuable information about defences and the morale of the occupation forces. Marian Sidor disguised as a labourer drew up plans of the fortifications in Jutland. Another cell based in Helsigør, provided information regarding shipbuilding and military sites in Zeeland. Genowefa Słobodziukówna also organised the escape of Polish POWs (Pepłoński, 2005; Kruszewski, 2016) and acquisition of arms and ammunition from the local garrison on Zeeland where conscripted Poles into the Wehrmacht assisted. Józef Wojtczak (he was killed on 8th September 1944) assisted Marian Sidor in developing escape routes over the German border to Sweden via Copenhagen or Nivå to Malmö and were met by Romana Heinzówna (Kruszewski, 2016). Marian Sidor was arrested in January 1943 just before a planned trip to Britain for SOE training.

In March 1944 the Gestapo made further arrests of members of FELICJA who now had agents and couriers from Poles, Danes, Czech’s, and Belgians resident in Denmark. The Gestapo had names but lacked evidence of their activities which included attempts to recruit conscripted Poles in the Wehrmacht and the Todt organization into cells (Williamson, 2012) that numbered around 500 men and later many would cross to Sweden over the Øresund Strait (Kruszewski, 2016). The repatriation of Poles caused a logistical and financial burden upon the mission with reports of desertions and executions circulated that included an incident at Oksbøl where conscripted Poles clashed with Wehrmacht soldiers. With the Germans taking over the Danes civil administration in 1943 resistance organizations found their ability to operate increasingly difficult due to elements of collaboration by local Danes. After 15th May 1944 underground operations became even more hazardous as the Germans stepped up patrols to suppress the Danish population and any underground activities by the Resistance. The Germans were assisted by the Schalburgers, who were Nazi sympathizers and the growth in summary executions failed to reduce the sabotage by the Danish resistance (Kruszewski, 2016).

E/ UP were also active in Denmark and like II Bureau’s operations, were directed from Sweden. A Polish schoolmistress SABINA was the focal point of the operations. While there was a hidden W/T set there was no one available to use it (TNA HS7-184). In addition, agent HELGA was in contact with the Danish resistance and her operation was funded through Sweden with £600,000 credit to cover operational expenses. On the capture of a courier on the Swedish-Danish border, HELGA’S position was compromised and escaped to Sweden and finally Britain. After her departure, more arrests of couriers and Poles followed. SABINA recognized there was a good flow of intelligence through her organization from the Baltic States and Scandinavia. During a meeting in Britain, she indicated the strength of the organization lay in the spreading of disinformation and black propaganda through the Polish community to destabilize the Wehrmacht occupation forces and report on specific factories and military installations. While the organization’s activities had been quite passive due to its size, it could not provide the Danish resistance the type of support needed but were able to assist in forming a link to M. Suidaks ‘line’ into and out of Poland’s ports through Sweden (TNA/ HS7-184). A ‘line’ from Germany into Denmark was organized by Genowefa Słobodziukówna in Haderslev and focused on extraction of Polish POWs being brought to Denmark. In July 1943 Józef Wojtczak took control of the group in Haderslev and began to focus on developing ‘cells’ in Kolding, Sønderburg and Kruså on the German border to improve the ‘line’ from Germany and collect intelligence on the morale of the German troops stationed in Denmark where the Muża brothers (Jan and Jozef) played a key role (Kruszewski, 2016) and passed the information to FELICJA agents Sonia Gergersen and William Josefson in Haderslev.

While there may be some disagreement over the effectiveness of FELICJA and E/ UP operations, the evidence demonstrates a significant contribution to ‘Continental Action’ and the destabilizing effect on the Nazi war effort through pinning down resources and personnel while at the same time undermining the morale of conscripted Poles into the Wehrmacht.

Sweden:

A political and diplomatic row erupted in the summer of 1942 between Britain, Sweden, and the Polish Ministry of Foreign Affairs in London (TNA/ HS4-135) when it was learned that both Sweden and Germany had broken their ciphers and been reading traffic between London and Stockholm. The result was that seven Swedish nationals’ resident in Poland had been arrested by the Gestapo for acting as agents transferring funds between the Polish Government in Exile in London to the Polish underground via the Polish Legation in Stockholm (TNA/ HS4-135). The Minister of the Interior, Stanisław Mikołajczyk who would later become the Prime Minister, was surprised the cypher had been broken when informed by Osóbka-Morawski (TNA/ HS4-135) and bowed to the Swedes demand that these types of operations would cease and focus on genuine diplomatic affairs. Mikołajczyk was nearly sacked over the incident by the incensed Sikorski with Britain’s Foreign Office describing the incident as a ‘criminally careless’ action.

Polish and Swedish intelligence services had developed a close relationship through cell GUSTAV headed by Maj. Szymaniak and was based on the distrust of the Soviets (Bennett, 2005) that resulted in the Poles sharing little of its Scandinavian intelligence with Britain and the Allies. The Polish legation in Stockholm (SKN) controlled the intelligence gathering activities in Sweden, Denmark and Norway, the latter being of less effective due to the Norwegians limited the intelligence and counterintelligence gathering by the Poles (Cell 3) (Bennett, 2005). Maj. Edmund Rózycki (Mazepa, Dziennikarz) headed the intelligence operation in Stockholm until June 1944 and was succeeded by Lt. Col. Władsław Łos (Bilecki) after his deportation. Working out of the Legation was a cell headed by Cmdr. Edmund Piotrowski (Pileski) under the guise of the Polish Red Cross (Bennett, 2005) and working in German occupied countries linked to an organisation ‘Base RENIFER’.

The Polish Legation covered intelligence, counterintelligence, economic warfare, and propaganda within Scandinavia and included Soviet backed communist activities. Station ‘Anna’ and substation ‘Północ’ was also based in Stockholm and run as a combined operation between II Bureau and VI Bureau to cover intelligence gathering in the Baltic states and often had intelligence from foreign labourers working in Germany passing on details of defence systems and factory output. ‘Północ’ was set up in January 1940 and headed by Capt. Wacław Gilewicz under the cover of 2nd Secretary of the Polish Legation. As an experienced intelligence officer, he had numerous contacts within Scandinavia, especially Denmark (Pepłoński, 2005) and prior to the Swedish posting was responsible for co-operating with the Japanese (McKay, 2020). Agent ‘Majer’ provided shipping intelligence on Malmö and activity on Bornholm including the departure of the Kriegsmarine fleet for the invasion of Norway. Col. Nishimura, the Japanese Military Attaché in Stockholm provided shipping and naval intelligence gathered in Haparanda and Boden (Pepłoński, 2005; McKay, 2020). Capt. Wacław Gilewicz was forced to leave Sweden when his cover was ‘blown’ by Swedish counterintelligence on 29th July 1941 and the station was renamed SKN.

There were several attempts to penetrate the Polish cells. Bernard Smolarczyk (Szmularczyk) had been evacuated at the beginning of 1940 and his cover story of his intention to travel to France aroused suspicion that he was working for the Germans. Again, in 1942 a German agent with a Polish Volksdeutsch pass, worked on a Swedish ship plying between Danzig and Swedish ports, contacted Edmund Rózycki to supply political information as agent Orzel. He was asked to supply shipping movements as a test and the Abwehr provided misinformation, however Orzel had been given names of agents in Göthenburg and Malmö putting the cells at risk, compromising operations and the integrity of the intelligence gathered (Bennett, 2005).

The legation worked in difficult conditions since the Swedes defended their neutrality and applied sanctions when there was clear evidence of overstepping ‘lines’ (Jaworski, 2009) with Sweden’s counterintelligence ramped up to cope with the sheer volume of spying operations by the Nazis, Soviets, the USA, and Britain (Lundberg, 2016). Rózycki’s successor, Władsław Łos was deemed to lack the drive and experience that resulted in the intelligence gathered as lower quality to be effectively used by the Allies (Bennett, 2005). Despite this, Zbigniew Folejewski (Styka), a Polish teacher based in Stockholm acted as a courier travelling relatively unrestricted between major urban centres throughout Sweden (Kruszewski, 2016).

Relations between Germany and Sweden became based on humiliating concessions to the Reich through various agreements such as the transit of troop trains to Norway via the port of Trelleborg or the evacuation of wounded after Narvik via Kiruna to ensure a degree of neutrality (Gilmour, 2011). These movements were watched by agents working in Stockholm’s station Płn/ SKN. SOE in Sweden was led by Peter Tennant (Karlsson) and was responsible for sabotaging the train station at Gudå close to the Swedish-Norwegian border in April 1941; a transport train at Krylbo in July 1941 carrying German munitions to Finland and the sinking of three Swedish destroyers anchored in Hårsfjärden (Lundberg, 2016). These incidents highlighted to both the Swedes and other foreign spy agencies the lengths the British would go to in their war effort

The bi-lateral relations between Poland and Sweden would only regain strength as the Reich suffered defeats on the Eastern Front (Foot, 1990) and by September 1943 Sweden was no longer providing concessions as the politicians turned towards stronger political and economic ties with Britain and the USA, despite Swedish public opinion still on the side of Germany (Foot, 1990; Jaworski, 2019). This is exemplified by the increasing number of flights carried out by the British Overseas Airways Corporation (BOAC) from Leuchars in Scotland to Bromma carrying diplomatic mail for both the British Embassy in Stockholm and the Polish Legation together with agents and couriers (Knowles, 2021) with the return flights carrying escapees, agents, and highly prized quality precision ball bearings for a range of transport needs, particularly aircraft engines.

Post Yalta, Swedish diplomats recognised the need to act as a ‘bridge’ between the East and West despite Stalin’s grab for Baltic states being of concern and potential threat to Sweden’s neutrality and sovereignty, specifically after the disappearance of Raoul Wallenberg who disappeared without trace on 17th January 1945 in Hungary. Giving any recognition to the Lublin provisional Government would be used as pro-Soviet propaganda and refusal would alienate or aggravate relations with the Soviets. In the end, on 7th July 1945, Sweden announced to Minister Zygmunt Modzelewski of the Lublin Government that Sweden no longer recognised the legitimacy of the Government in Exile in London. Sweden’s support for the Soviet backed communist government and the settling of the Curzon Line indicated concession and recognition of Stalin’s ‘faits accomplis’ (Jaworski, 2019). Polish submarines (Sęp, Ryś and Żbik) detained in Sweden since the outbreak of war were returned to Poland. The crew of the submarines were not idle. The crew used radio communications on behalf of station Anna to London and intercepted coded German dispatches from Norway (Pepłoński, 2005).

POWs from the Narvik campaign and downed aircrew mostly chose to go to Britain with the newly established communist backed government being of little attraction. A further 4,800 soldiers from Britain, Norway and Germany would be slowly repatriated at the war’s end.

In the spring of 1945 Sweden launched its ‘White Buses’ operation through the Swedish Red Cross to ultimately save 15,500 Holocaust victims and some Polish POWs in Germany (Greayer and Sjöstrand, 2000). Sweden had remained compassionate and managed to represent Poland’s interests where possible in a complex intertwined circus ring between the Soviets, the Reich, the Allies, and the Soviet backed Lublin Committee (Jaworski, 2009).

Jaworski (2019) concluded that Polish-Swedish relations can be clearly divided into several stages and based on the ‘tide’ of the war. Their strategy was ‘flexible neutrality’ to balance Sweden’s neutrality and the eventual power struggle between the Reich, Soviets and then finally the Allies and the Soviets as the ‘Cold War’ dawned. A continued game of diplomatic chess preoccupied the representatives of their respective governments throughout the war.

Selected References:

Andersen, S. (2016) “A Mild Occupation? Denmark, 1940-1945” in “Paying for Hitler’s War: The Consequences of Nazi Hegemony for Europe”,in Scherner, J and White, E.N. (Eds), Cambridge University Press, UK Ch.11.

Bennett, G. (2005) “Scandinavia and the Baltic States” in Sterling, T; Nałecz, D and Dubicki, T (Eds) “The Report of the Anglo-Polish Historical Committee Vol.1”, Valentine Mitchel, UK, Ch.33.res Mondiales et Conflits Contemporains, Vol.218, No. 2, pp. 67-83.

Bułhak, W. (2005) “SOSAINT – Socially Assisted Intelligence: Polish Intelligence in Denmark during World War II”,International Journal of Intelligence and Counterintelligence, (https://doi.org/10.1080/08850607.2023.2173922) (Accessed 06.08.2023)

Bułhak, W. (2023) “A Centenary of Polish-Danish Relations”, Studien zur Geschichte der Europäischen Integration / Études sur l’Histoire de l’Intégration Européenne / Studies on the History of European Integration, Vol.37, Franz Steiner Verlag, Germany.

Davies, N. (2001) “Heart of Europe: The Past in Poland’s Present”, OUP, UK.

Djursaa, M. (1980) “Who were the Danish Nazis? A methodological report on an ongoing project”. In R. Mann (Ed.), “Die Nationalsozialisten: Analysen faschistischer Bewegungen” pp. 137-154.

Foot, M.R.D. (1990) “SOE: The Special Operations Executive 1940-46, Mandarin Book, UK.

Gilmour, J. (2011) “Sweden, the Swastika and Stalin: The Swedish experience in the Second World War”, Edinburgh University Press, Ch.3

Greayer, A. and Sjöstrand, S. (2000) “The White Buses: The Swedish Red Cros Rescue Action in Germany during the Second World War”, The Swedish Red Cross, Sweden.

Insall, T. (2021) “Special Operations and Intelligence in Norway 1940-1945”, Biteback Publishing, UK.

Jaworski, P. (2009) Marzyciele i oportuniści: Stosunki polsko-szwedzkie w latach 1939–1945”, IPN, Poland.

Jaworski, P. (2015) “Polish experiences with Scandinavian activity in the League of Nations”, Scandinavian Journal of History, Vol.40, No.5, pp. 610-632.

Jaworski, P. (2019) “Polish-Swedish Relations During the Second World War”, Södertörn Academic Studies 73, Sweden

Kłonczyński, A. (2016) “nationally and Religiously: Commemorations in the Life of the Polish Diaspora in Sweden 1945-1989”, Polish American Studies, Vol. LXXIII, No.2, pp. 83-97.

Knowles, M. (2021) “The BOAC Leuchars-Bromma Service 1939-1945”, IFS Insights, No.4, pp.1-20

Kochanski, H. (2012) “The Eagle Unbowed: Poland and the Poles in the Second World War”, Allan Lane, UK.

Kruszewski, E.S. (2016) “Kaszubi w polskiej organizacji ‘Felicja’ w Denii (1940-1945)”, Acta Cassubiana, No. 18, pp.169-187.

Lundberg, V. (2016) “Karlsson, the Amiable Spy: Swedish Experiences of Allied espionage and Sabotage during World War II”, La voce del silenzio, No. 28, (https://doi.org/10.4000/diacronie.4709) (Accessed 05.08.2023)

Makiłła, D. (2016) “The Second Northern War (1655-1660) as a Casus of the Early Modern Geopolitics”, Studia Maritima, Vol. 29, pp. 83-113.

McKay, C.G. (2020)“From Information to Intrigue: Studies in Secret Service Based on the Swedish Experience, 1939-1945”, Routledge, UK.

Olsson, S. (1988) “Swedish-Polish trade negotiations at the end of the second world war and their results”, Scandinavian Economic History Review, Vol.36, No.2, pp. 30-41 published online https://doi.org/10.1080/03585522.1988.10408115 (Accessed 15.08.2023).

Overy, R.J. (1998) “Strategic Intelligence and the Outbreak of the Second World War”, War in History, Vol.5, No.4 pp.451-480.

Padelford, N.J. and Gösta A. Andersson. (1939) “The Aaland Islands Question”, The American Journal of International Law, Vol.33, No. 3, pp. 465-487.

Pepłoński, A. (2005) “The Operation of the Intelligence Services of the Ministry of Internal Affairs (MSW) and of the Ministry of national Defence (MON), in Sterling, T; Nałecz, D and Dubicki, T (Eds) “The Report of the Anglo-Polish Historical Committee Vol.1”, Valentine Mitchel, UK, Ch11.

Pepłoński, A. (2005) “Scandinavia and the Baltic States”, in Sterling, T; Nałecz, D and Dubicki, T (Eds) “The Report of the Anglo-Polish Historical Committee Vol.1”, Valentine Mitchel, UK, Ch34.

Śmigielski, R. (2022) “130 Years of Polish Migration in Denmark”, Studia Polonije, No.43, pp. 115-127.

Sørensen, M.J. (2017) “Glorifications and Simplifications in Case Studies of Danish WWII Nonviolent Resistance”, Journal of Resistance Studies, Vol. 3, No. 1, pp. 99-137.

Suonpää, M. (2022) “Swedish and British security officialdom, a suspected spy, and information management in the era of the Second World War”, Journal of Intelligence History, (https://doi.org/10.1080/16161262.2022.2099189) (Accessed 05.08.2023)

Tingsten, H. (1959) “Issues in Swedish Foreign Policy”,Foreign Affairs, Vol.37, No. 3, pp. 474-485.

Williamson, D.G. (2012) “The Polish Underground 1939-1947”, Pen & Sword Military, UK.

Winter, P.R.J. (2011) “Penetrating Hitler’s High Command: Anglo-Polish HUMINT, 1939-1945”, War in History, Vol.18, No.1, pp.85-108.

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