Major Events of August 1939: Key Historical Moments from the Month
Each month is marked by defining moments that shape the course of history. Whether through political shifts, cultural movements, or world-changing events, these periods leave a lasting impression. Dive into the most important events from August 1939 and discover how they influenced the world both then and now.

Major Events of August 1939: Key Historical Moments from the Month
- 01 Aug 1939 German Invasion of Poland - Start of World War II: On August 1, 1939, Nazi Germany launched a massive, unprovoked military invasion of Poland, marking the beginning of World War II. The German Wehrmacht deployed an overwhelming force of 60 divisions, totaling approximately 1.5 million soldiers, supported by a formidable mechanized and aerial assault. The invasion force included over 2,000 tanks, nearly 900 bombers, and more than 400 fighter planes, demonstrating Germany's strategic military superiority and aggressive expansionist intentions. This coordinated attack, known as the September Campaign or Fall Weiss (Case White), swiftly overwhelmed Polish defenses and set the stage for the global conflict that would follow.
- 02 Aug 1939 Einstein and Szilard Warn Roosevelt About Nuclear Potential: Albert Einstein and Leo Szilard collaborate on a critical letter to President Franklin D. Roosevelt, alerting him to the potential development of an atomic weapon by Nazi Germany and urging the United States to begin research into nuclear technology. This historic communication would ultimately lead to the Manhattan Project, a secret research and development program that would dramatically alter the course of World War II and global geopolitics.
- 03 Aug 1939 Nazi Persecution of Jewish Doctors: In a stark escalation of antisemitic policies, Nazi Germany nullified the medical licenses of all Jewish doctors, systematically removing Jewish professionals from the healthcare system and marking another devastating step in the regime's persecution of Jewish citizens.
- 04 Aug 1939 British Parliament Prorogued Before World War II: Prime Minister Neville Chamberlain officially dismisses the British Parliament, scheduling its reconvening for October 3rd, 1939. This prorogation occurs during a critical period of escalating international tensions, just weeks before the outbreak of World War II.
- 05 Aug 1939 The Thirteen Roses Execution: On August 5, 1939, thirteen young female members of the Unified Socialist Youth were executed by Francoist forces in Madrid, Spain. These women, known as 'Las Trece Rosas' (The Thirteen Roses), were primarily young activists who were killed in the aftermath of the Spanish Civil War, symbolizing the brutal repression of political dissidents during Francisco Franco's regime.
- 06 Aug 1939 Dinah Shore Radio Debut: Dinah Shore, a renowned American singer, actress, and television personality, made her first national radio broadcast on NBC, marking the beginning of her influential media career.
- 07 Aug 1939 Pre-World War II Period - Tensions Rising: While no specific documented event is recorded for this exact date, August 1939 was a critical period of escalating international tensions preceding World War II. Just days before the Nazi invasion of Poland, diplomatic and military preparations were intensifying across Europe. The world was on the brink of a massive global conflict, with Nazi Germany and the Soviet Union secretly negotiating the Molotov-Ribbentrop Non-Aggression Pact, which would be signed on August 23, 1939.
- 08 Aug 1939 Large-Scale British Air Defence Demonstration: On August 8, 1939, the United Kingdom conducted an extensive air defence exercise involving 1,300 military aircraft. This massive aerial demonstration was a critical preparatory measure in the weeks leading up to World War II, showcasing Britain's military readiness and air power capabilities. The test was designed to assess the Royal Air Force's defensive strategies, coordination, and response times in anticipation of potential aerial threats.
- 09 Aug 1939 Romano Prodi Becomes European Commission President: Romano Prodi, a prominent Italian politician and economist, assumed the role of President of the European Commission, serving from 1999 to 2004. During his tenure, he played a crucial role in advancing European integration, overseeing significant policy developments and preparing for the expansion of the European Union to include several Eastern European countries.
- 10 Aug 1939 Formation of De Geer Government with Social Democrats: On August 10, 1939, the second Dutch government led by Dirk Jan de Geer was formed, marking a significant political milestone as it was the first Dutch government to include Social Democrats in its coalition. This development reflected the evolving political landscape of the Netherlands in the late 1930s, just before the outbreak of World War II.
- 11 Aug 1939 Sergei Rachmaninoff's Final European Concert Performance: On August 11, 1939, renowned Russian composer and pianist Sergei Rachmaninoff gave his last concert performance in Europe before the impending outbreak of World War II. This poignant moment marked the end of an era for the celebrated musician, who would soon emigrate permanently to the United States, leaving behind the continent of his birth.
- 12 Aug 1939 Tripartite Military Negotiations in Moscow: Military representatives from the Soviet Union, France, and Britain convened in Moscow to explore potential strategic alliance options amid rising tensions in Europe. These discussions were critical in the lead-up to World War II, as the major powers sought diplomatic and military solutions to the growing threat of Nazi Germany's expansionist policies.
- 13 Aug 1939 Count Ciano's Ominous Warning About German Aggression: Count Galeazzo Ciano, Italian Foreign Minister and son-in-law of Benito Mussolini, returned to Italy with a grave assessment of the impending European conflict. After diplomatic discussions, he was convinced that Nazi Germany was irrevocably committed to war. In his personal diary, he dramatically noted that Germany was 'possessed by the demon of destruction' and would likely initiate conflict regardless of diplomatic concessions.
- 14 Aug 1939 First Night Baseball Game at Comiskey Park: On August 14, 1939, Comiskey Park in Chicago hosted its inaugural night baseball game, marking a significant milestone in baseball history. The Chicago White Sox defeated the Saint Louis Browns 5-2 under the lights, ushering in a new era of baseball entertainment that would transform the sport's viewing experience. Night games allowed working-class fans to attend matches after their workday and dramatically increased stadium attendance and revenue.
- 15 Aug 1939 The Wizard of Oz Hollywood Premiere: The iconic MGM musical 'The Wizard of Oz', starring Judy Garland, premiered at Grauman's Chinese Theater in Los Angeles, California. This landmark film would go on to become one of the most beloved movies in cinema history.
- 16 Aug 1939 Critical Intelligence Transfer: Enigma Machine Obtained: Captain Bertrand of the French Signals Intelligence provides a Polish-built replica of the German Enigma coding machine and related materials to a British Secret Service Liaison officer, a pivotal moment in intelligence gathering just before World War II.
- 17 Aug 1939 The Wizard of Oz Premieres in New York: The iconic film 'The Wizard of Oz', starring Judy Garland, opens at Loew's Capitol Theater in New York City. This landmark movie, based on L. Frank Baum's beloved children's novel, would go on to become one of the most celebrated films in cinematic history, introducing the world to memorable characters like Dorothy, the Scarecrow, the Tin Man, and the Cowardly Lion.
- 18 Aug 1939 German Occupation of Slovakia: On August 18, 1939, Nazi Germany completed its strategic military occupation of Slovakia, effectively transforming the country into a puppet state and expanding its territorial control in Central Europe. This occupation was a critical prelude to World War II, demonstrating Germany's aggressive expansionist policy under Adolf Hitler's leadership.
- 19 Aug 1939 Nazi Germany Prepares for Invasion of Poland: Adolf Hitler orders the Kriegsmarine (German Navy) to initiate preliminary operations for 'Fall Weiss' (Case White), the planned invasion of Poland. German naval vessels and submarines are positioned for the impending military campaign. According to historian William L. Shirer, Hitler was anxious about the timing of negotiations with the Soviet Union, concerned that diplomatic delays might disrupt the invasion schedule.
- 20 Aug 1939 Nazi-Soviet Non-Aggression Pact Announced: Nazi Germany and the Soviet Union shocked the international community by announcing a surprising trade and non-aggression pact, a pivotal diplomatic agreement that would dramatically reshape the geopolitical landscape on the eve of World War II.
- 21 Aug 1939 Nazi-Soviet Non-Aggression Pact Confirmed: On August 21, 1939, Adolf Hitler received a telegram from Josef Stalin confirming the Molotov-Ribbentrop Pact, a non-aggression agreement between Nazi Germany and the Soviet Union. Hitler's excited reaction - banging his fist on the table and exclaiming "I have them!" - revealed his strategic satisfaction with the diplomatic breakthrough. This secret protocol effectively divided Eastern Europe into German and Soviet spheres of influence, setting the stage for the imminent invasion of Poland and the start of World War II.
- 22 Aug 1939 Hitler's Decisive War Speech to Military Leadership: In a pivotal address to his military commanders-in-chief, Adolf Hitler explicitly announced his strategic decision to invade Poland. During this speech, he outlined his motivations for the impending military action and candidly discussed potential international repercussions, setting the stage for the outbreak of World War II.
- 23 Aug 1939 Molotov-Ribbentrop Pact Signed: In a pivotal diplomatic moment, Nazi Germany and the Soviet Union signed a Treaty of Non-Aggression in Moscow. The agreement included a secret protocol that strategically divided Eastern Europe into spheres of influence. The Soviet Union would gain control of eastern Poland, Finland, Latvia, Estonia, and Bessarabia, while Germany would control western Poland and Lithuania. This pact shocked the world and set the stage for the imminent invasion of Poland, effectively triggering World War II.
- 24 Aug 1939 Molotov-Ribbentrop Pact Signed: Nazi Germany and the Soviet Union signed a 10-year non-aggression pact, secretly agreeing to divide Eastern European territories between themselves. This shocking diplomatic agreement stunned the international community and set the stage for the imminent invasion of Poland.
- 25 Aug 1939 Poland-Britain Mutual Assistance Agreement: In London, a critical Agreement of Mutual Assistance is signed between Poland and Great Britain, establishing a formal military alliance. The treaty stipulates that if Germany attacks either nation, the other will provide military support and defense.
- 26 Aug 1939 Belgium Mobilizes for Potential Conflict: As tensions escalated in Europe, Belgium initiated a national mobilization of its military forces in response to growing geopolitical uncertainties.
- 27 Aug 1939 First Jet Aircraft Flight by Erich Warsitz: On August 27, 1939, German test pilot Erich Warsitz made history by piloting the Heinkel He-178, the world's first jet-propelled aircraft. This groundbreaking flight marked a pivotal moment in aviation technology, demonstrating the potential of jet propulsion and revolutionizing aerospace engineering.
- 28 Aug 1939 German Troop Buildup Observed on Polish Border: British journalist Clare Hollingworth (corrected name spelling) makes a critical observation of massive German military preparations, witnessing 'hundreds of tanks, armored cars, and field guns' positioned along the Polish border, signaling imminent invasion.
- 29 Aug 1939 DUPE - Hitler's Diplomatic Maneuver: Adolf Hitler proposes a diplomatic meeting with Polish leadership, suggesting negotiations. However, this gesture was largely performative, as Warsaw swiftly rejected the invitation to send a delegation to Berlin. This event was part of the escalating tensions that would lead to the invasion of Poland and the start of World War II.
- 30 Aug 1939 Nazi Germany Initiates Invasion of Poland: Adolf Hitler orders German armed forces to launch a strategic military invasion of Poland, marking a critical moment that effectively triggers the start of World War II in Europe.
- 31 Aug 1939 Hitler's Invasion Order: At 12:40 pm on August 31, 1939, Adolf Hitler formally issued orders for military hostilities against Poland, scheduling the invasion to commence at 4:45 the following morning, marking the imminent outbreak of World War II.