May 1939

May 3rd, 1939

Second Sino-Japanese War: The Japanese Imperial Army launches new offensives in China, advancing in Hunan province. Chinese forces fortify urban centres to delay Japanese progress.

Great Britain and France negotiate with Germany: British and French diplomatic efforts to deter German aggression continue, but Hitler remains unmoved. German media amplifies anti-Polish propaganda, setting the stage for justifying future military actions.

Soviet Union Politics: Vyacheslav Molotov succeeds Maxim Litvinov as the People’s Commissar for Foreign Affairs. This leadership change paves the way for the Soviet-German rapprochement later that year.

May 4th, 1939

Germany prepares for War: Germany strengthens its western defences along the Siegfried Line, preparing for possible Allied retaliation in the event of war with Poland.

Preperations Fall Weiß: Military drills continue along the Polish border.

Soviet Union prepares for War: The Soviet Union increases border fortifications in the Far East, preparing for potential conflicts with Japan following clashes at the Manchurian border.

May 5th, 1939

Poland prepares for War: Poland enhances its defensive planning, reinforcing border fortifications and conducting military exercises. Polish leadership remains confident in British and French support in the event of war.

Second Sino-Japanese War: Japanese air raids target Chinese industrial centres, aiming to cripple the Nationalist war effort.

United States is Concerned: The United States voices concerns over Japanese aggression but takes no direct action.

May 6th, 1939

Preperations Fall Weiß: Germany’s military command evaluates logistical challenges for a large-scale invasion, focusing on rapid troop movements and supply chain security.

Great Britain prepares for War: The British government accelerates air raid precaution measures, anticipating future conflicts.

Great Britain is informed about talks bewteen Germany and the Soviet Union: Carl Friedrich Goerdeler informs the British government about a secret rapprochement between Germany and the Soviet Union, aiming to divide Eastern Europe between them. He also highlights Germany’s economic problems, suggesting that a firm British stance in support of Poland could deter Hitler from initiating war.

May 7th, 1939

Italy and Germany announce intentions for Alliance: Italy and Germany announced their intention to sign a military alliance to “contribute effectively to assuring peace in Europe.” This announcement foreshadowed the formalization of the Pact of Steel later that month, solidifying the Axis powers’ military cooperation.

Soviet Union and Germany Negotiate: The Soviet Union continues negotiating with Britain and France for a potential alliance against Germany. However, mutual distrust slows progress.

Japan prepares for War: Japanese naval forces conduct fleet exercises near Taiwan, demonstrating maritime strength.

May 8th, 1939

Great Britain tries to mediate: Great Britain offers to mediate in the German-Polish dispute over the Free Town of Danzig.

Germany prepares for War: German U-boats conduct training exercises in the Baltic, refining submarine warfare strategies. The Royal Navy monitors developments, preparing countermeasures against potential German naval threats.

Second Sino-Japanese War: China reorganises its defensive strategies, anticipating further Japanese advances in the summer.

May 9th, 1939

Visit of Lithuanian Defense Minister to Warsaw: General Stasys Raštikis, the Defence Minister of Lithuania, visits Warsaw, Poland. This visit occurrs during a period of heightened diplomatic activity in Eastern Europe.

Germany prepares for War: Germany increases arms shipments to Slovakia, reinforcing its sphere of influence in Central Europe.

German-Italian Alliance: Hitler continues to assure Mussolini of German-Italian cooperation in future military conflicts.

Second Sino-Japanese War: The Battle of Nanchang, a significant conflict during the Second Sino-Japanese War, concludes with a Japanese victory. The Chinese are forced to withdraw.

Spain’s Withdrawal from the League of Nations: Francoist Spain announced its withdrawal from the League of Nations, reflecting the country’s political realignment following the Spanish Civil War.

May 10th, 1939

Great Britain and France warn Germany: The British and French governments issue new diplomatic warnings to Germany regarding Poland. However, Hitler remains focused on his territorial ambitions.

United States considers helping China: The United States debates increasing military aid to China, though official policies remain non-interventionist.

Holocaust: The Hungarian government enacts a series of discriminatory laws targeting the Jewish population, significantly escalating state-sanctioned persecution. These laws systematically strip Hungarian Jews of their civil liberties, restricting their rights in employment, education, and social participation.

May 11th, 1939

Soviet–Japanese Border Conflicts: The Battle of Khalkhin Gol begins as Mongolian/Soviet and Japanese forces clash on the Mongolian-Manchurian border. Initial skirmishes begin when a Mongolian cavalry unit entered the disputed area, leading to clashes with Manchukuoan forces.

May 12th, 1939

Preperations Fall Weiß: Germany finalises plans for “Fall Weiss” (Case White), the invasion of Poland. The Wehrmacht continues logistical preparations for war.

Soviet–Japanese Border Conflicts: Japan reinforces its positions in Manchuria, escalating border tensions with the Soviet Union. Stalin orders additional Red Army units to the region, ensuring a strong Soviet response.

Anglo-Turkish Security Pact Signed: Great Britain and Turkey formalise a strategic security agreement, strengthening their diplomatic and defensive ties in the lead-up to World War II. This bilateral pact is part of broader European efforts to establish alliances in anticipation of potential conflicts with Germany.

Polish-French Mutual Assistance Agreement: In Paris, Polish Ambassador Juliusz Łukasiewicz and French Foreign Minister Georges Bonnet sign a mutual assistance agreement between Poland and France. This pact was aims at providing mutual support in the event of aggression, reflecting the tense geopolitical climate of the time.

May 13th, 1939

MS St. Louis Sets Sail: The German ocean liner MS St. Louis departs from Hamburg, Germany, carrying 937 passengers, most of whom are Jewish refugees seeking asylum from Nazi persecution. The ship’s intended destination was Havana, Cuba, but upon arrival, the passengers are denied entry. Subsequently, the United States and Canada also refuse to admit them, forcing the ship to return to Europe. Many of these refugees later become victims of the Holocaust.

Soviet–Japanese Border Conflicts: Soviet forces launch counteroffensives against Japanese positions at Khalkhin Gol, resulting in heavy casualties on both sides.

Great Britain and France prepare for War: British and French intelligence report increased German troop movements near the Polish border, raising concerns over imminent aggression.

Sinaia Agreement Enacted: The Sinaia Agreement, initially signed on August 18, 1938, between Romania, France, and the United Kingdom, comes into effect. This agreement transfers most of the powers of the European Danube Commission to the Romanian state, granting Romania control over the Danube’s maritime navigation from Brăila to the Black Sea.

Italian Support for Germany: Galeazzo Ciano, the Italian Minister of Foreign Affairs, informs Polish Foreign Minister Józef Beck that in the event of a future conflict between Poland and Germany, Italy will support Germany.

May 14th, 1939

Adolf Hitler’s Inspection: Adolf Hitler visited Aachen to inspect the Siegfried Line, a series of fortifications along Germany’s western border.

Japan prepares for War: The Japanese Imperial Navy conducts fleet manoeuvres in the South China Sea, testing potential strategies for controlling vital trade routes.

Poland warns Germany: The Polish government warns Germany against border provocations, reaffirming its commitment to defending national sovereignty.

Short Stirling’s Maiden Flight: The prototype of the Short Stirling, the first four-engined British heavy bomber of World War II, conducted its first flight.

May 15th, 1939

Holocaust: The SS establishes Ravensbrück, the largest concentration camp for women, located north of Berlin, Germany.

Germany and Italy improve their Alliance: Germany and Italy strengthen military ties, exchanging technological and strategic insights. Mussolini promises Hitler continued support but remains cautious about direct military engagement.

Inauguration of Caselle Torinese Airfield: Italian dictator Benito Mussolini attended the opening of a new military airfield in Caselle Torinese, situated approximately 40 kilometres from the French border.

Soviet–Japanese Border Conflicts: The Battle of Khalkhin Gol continues, with Soviet forces attempting to encircle Japanese positions.

Eva Braun Mentioned in International Press: For the first time, Eva Braun is mentioned in the international press. A Time magazine article speculates about the personal lives of Adolf Hitler and Benito Mussolini, identifying Braun as someone Hitler visits whenever he was in Munich.

Fairchild M-62 First Flight: The Fairchild M-62, which will later be designated as the PT-19, had its maiden flight on this day.

May 16th, 1939

Poland prepares for War:: In response to escalating tensions in Europe, General Wacław Stachiewicz ordered the development of fortification plans along the Polish-German border.

Great Britain prepares for War: The British Royal Air Force conducts air defence drills, anticipating potential German aerial attacks.

United States increases Diplomacy in Asia: The United States increases its diplomatic efforts in Asia, warning Japan against further territorial expansion.

May 17th, 1939

Non-Agression pact declined: Sweden, Norway, and Finland declined Germany’s proposal for non-aggression pacts.

Germany prepares for War: Germany’s industrial sector continues ramping up military production, particularly in tank and aircraft manufacturing.

Soviet Union prepares for War: The Soviet Union expands military fortifications along its western border, wary of future German aggression.

Palestine: The British government issues the White Paper of 1939 concerning Mandatory Palestine. This policy document proposes limiting Jewish immigration to the region, aiming to maintain the Jewish population at one-third of the total.

May 18th, 1939

Poland and Great Britain prepare for War: Polish and French military officials discuss coordination in the event of a German invasion. However, logistical challenges limit France’s ability to offer immediate support.

Second Sino-Japanese War: Japan reinforces its hold over occupied Chinese ports, restricting international trade to weaken Chinese resistance.

Palestine: In Jerusalem, Jewish residents protest against the British White Paper, which severely restricted Jewish immigration to Mandatory Palestine. The demonstrations escalate into riots, resulting in approximately 100 injuries.

May 19th, 1939

Preperations Fall Weiß: Germany deploys additional Panzer divisions near the Polish border, conducting last-minute war exercises.

Soviet–Japanese Border Conflicts: The Battle of Khalkhin Gol intensifies as both sides suffer heavy casualties. Soviet artillery proves effective against Japanese fortifications.

Franco’s Victory Parade in Spain: Spanish Head of State Francisco Franco presides over the first victory parade in Madrid, marking the end of the Spanish Civil War.

May 20th, 1939

Germany provocates Poland: A group of German Sturm Abteilung troopers attack and ransack a Polish customs house in Kalthof. During the incident, Gustav Gruebner, one of the Sturm Abteilung men, is shot and killed by a Polish chauffeur.

Soviet–Japanese Border Conflicts: Japan considers escalating the conflict at Khalkhin Gol but hesitates due to mounting Soviet resistance.

Great Britain prepares for War: The Royal Navy expands its patrols, ensuring British dominance in European waters.

May 21st, 1939

French and British Diplomacy: British and French diplomats continue attempting to negotiate peace with Germany, but Hitler remains committed to military solutions.

First flight of the Ilyushin DB-3F: The Soviet Union conducts the maiden flight of the Ilyushin DB-3F, a long-range bomber later redesignated as the Ilyushin Il-4.

May 22nd, 1939

Pact of Steel: Germany and Italy sign the Pact of Steel, officially known as the Pact of Friendship and Alliance between Germany and Italy. This agreement solidifies a military and political alliance between the two nations. The pact consists of two main parts: an open declaration of continuing trust and cooperation, and a “Secret Supplementary Protocol” that encourage unified military and economic policies. The signing takes place in the Reich Chancellery in Berlin, with German Foreign Minister Joachim von Ribbentrop and Italian Foreign Minister Galeazzo Ciano representing their respective countries.

May 23rd, 1939

Adolf Hitler’s Directive to Attack Poland: In a meeting with top military officials in Berlin, Adolf Hitler announces his decision to attack Poland at the first suitable opportunity. He emphasizes that the conflict over Danzig is not the primary issue; instead, the goal is to expand Germany’s living space in the East and secure food supplies.

Mandatory Palestine: Several kibbutzim are established on this day, including Mahanayim, Shadmot Dvora, HaZore’im, and Kfar Glikson. These communal settlements play a crucial role in the development of Jewish society in the region.

Polish-British Military Negotiations: In Warsaw, military negotiations between Poland and Great Britain commence, reflecting the escalating tensions in Europe and the efforts to form strategic alliances in anticipation of potential conflicts.

May 24th, 1939

Poland Mobilises: Poland increases recruitment efforts, strengthening its armed forces in response to rising German threats.

Fleet Air Arm Transition: The British Royal Navy assumes control of its naval aviation assets from the Royal Air Force, officially establishing the Air Branch of the Royal Navy. Although the term “Fleet Air Arm” remains in informal use, this transition marked a significant organisational change in British naval aviation.

Second Sino-Japanese War: The Battle of Suixian-Zaoyang concludes with a significant victory for Chinese forces, marking a pivotal moment in their resistance against Japanese military expansion.

May 25th, 1939

Soviet–Japanese Border Conflicts: Japanese forces at Khalkhin Gol attempt a breakthrough, but Soviet counterattacks repel their advances. The conflict remains at a stalemate.

Arrest of Fritz Julius Kuhn: Fritz Julius Kuhn, leader of the German American Bund, a fascist pro-German organisation in the United States, is arrested on charges of forgery and grand larceny.

First flight of the Henschel Hs 129: The maiden flight of the Henschel Hs 129, a German ground-attack aircraft.

May 26th, 1939

Germany prepares for War: Germany accelerates its U-boat production, preparing for future naval engagements against Great Britain and France.

Great Britain’s Military Preparations: The Military Training Act received Royal Assent, marking the UK’s first peacetime conscription law, requiring men aged 20 and 21 to undergo six months of military training.

Condor Legion’s Departure from Spain: German personnel of the Condor Legion, who supported Franco’s forces during the Spanish Civil War, departs Spain, marking the end of their involvement in the conflict.

May 27th, 1939

Soviet Union prepares for War: The Soviet Union receives intelligence reports of Germany’s increasing hostility, heightening suspicions of an eventual German invasion.

U.S. Neutrality Act Discussion: U.S. Secretary of State Cordell Hull writes to the Senate Foreign Relations Committee, advocating for the repeal of the arms embargo provision in the U.S. Neutrality Act, signaling a shift in U.S. foreign policy as global tensions escalate.

May 28th, 1939

Great Britain and France prepare for War: British and French high commands discuss long-term war preparations, recognising Germany’s growing military strength.

Mandatory Palestine: In Mandatory Palestine, the moshav (a type of cooperative agricultural community) named Mishmar HaYam was established.

May 29th, 1939

Hungarian Parliamentary Elections: The two-day parliamentary elections in Hungary conclude, with the Party of Hungarian Life securing a majority. The fascist Arrow Cross Party finishes second.

Soviet–Japanese Border Conflicts: Japan reassesses its strategies at Khalkhin Gol, planning a renewed offensive in the coming months.

May 30th, 1939

Germany Mobilises: Germany expands military recruitment efforts, preparing for prolonged conflict. Hitler demands final preparations for war be completed by late summer.

May 31st, 1939

Germany-Denmark Non-Aggression Pact: Nazi Germany and Denmark signs a non-aggression pact, aiming to maintain peaceful relations between the two nations.

Celebration of German Veterans from the Spanish Civil War: In Hamburg, a ceremonial event is held to honour 5,000 German fighters who have participated in the Spanish Civil War. Hermann Göring, personally distributes 36 gold crosses for extraordinary valour, symbolising Germany’s military involvement in the Spanish conflict.

Italian Forces Depart Spain: Italian forces, including the “legionary air force,” conclude their involvement in the Spanish Civil War and depart from Spain.