Finding Dulcinea Logo New
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

On This Day: Nazi Germany Invades Poland, Starting World War II

Last updated: February 13, 2023

On Sept. 1, 1939, Nazi Germany launched an invasion of Poland. Two days later, Polish allies Britain and France declared war on Germany, marking the start of World War II.

The September Campaign

In the early morning hours of Sept. 1, 1939, 1.5 million German troops invaded Poland by air and by land, unleashing the first “blitzkrieg,” a strategy meaning “lightning war.” Planes, tank and air forces were deployed with stunning speed, and troops destroyed railroads and communications stations, infiltrated strongholds by posing as Polish military officers, and killed enemies with explosives, guns and even sabers.

Hours after the attack, German Chancellor Adolf Hitler went before the Reichstag and claimed that Germany had launched an attack in response to Polish aggressiveness. “For the first time Polish regular soldiers fired on our own territory,” he said. “Since 5:45 a.m. we have been returning the fire, and from now on bombs will be met with bombs.”

France and England declared war against Germany on Sept. 3, but their support was nominal at best. Neither country deployed significant military forces until the next year, leaving Poland alone in its defense.

Although it had an army of more than 700,000, Poland was unprepared for the blitzkrieg tactics. Its army was built around the tactics of World War I and it could not deploy its troops quickly enough to defend against the more powerful German forces.

Any hopes of repelling the invasion were dashed on Sept. 17, when the Soviet Red Army invaded from east. Many Polish soldiers fled to Romania and formed resistance forces. By the end of September, Germany and the Soviet Union had control of the country. The last organized Polish resistance was defeated on Oct. 6.

Background: Hitler’s Foreign Aggression

Sources in this Story

  • The History Place: The Triumph of Hitler: The Last Days of Peace
  • Yale Law School: The Avalon Project: The British War Bluebook: Speech by Herr Hitler to the Reichstag on September 1, 1939
  • EyeWitness to History: Britain Declares War on Germany, 1939
  • Poland in Exile: The Polish September Campaign 1939
  • JUK National Archives: Chamberlain and Hitler 1938
  • The BBC: Invasion of Poland
  • Encyclopedia Britannica: German-Soviet Nonaggression Pact
  • History Learning Site: The Phoney War
  • Library of Congress: Country Studies: Poland: World War II

Hitler felt that the seizure of foreign land for German use, known as Lebensraum, was necessary for the German economy. In defiance of the Treaty of Versailles, he began rearmament, seized the Rhineland in 1936, formed a union with Austria (Anschluss) in March 1938, and pushed for Czechoslovakia to cede the Sudetenland, a region with a large German minority.

Britain and France responded with appeasement, allowing Hitler to take control of the region in September 1938 under the condition that he seize no more territory. In March 1939, he seized the rest of the country; France and Britain did little in response.

His next target was Poland, specifically the industrial port city of Danzig (present-day Gdansk) on the German border, which had been ceded to Poland in the Treaty of Versailles. In April, Poland formed a military alliance with Britain that would guarantee British intervention if Germany invaded Poland.

Undeterred, Hitler and his generals formed plans for the invasion of Poland through the spring and summer. Hitler feared that it might provoke the Soviet Union and leave Germany fighting a two-front war. On Aug. 23, 1939, Germany signed a non-aggression pact with the Soviet Union, known as the Molotov-Ribbentrop pact.

The invasion was set to begin three days later, but it was called off just hours before, after Italian Prime Minister Benito Mussolini, Hitler’s ally, said that his country was not yet prepared for war. The invasion was delayed until Sept. 1.

Reactions: The “Phony War”

After the initial rapid attacks on Poland, things appeared to quickly quiet down. News was sparse from the front lines, and the American press started referring to the situation as the “phony war.”

Actually, while there were few explosions or military engagements, there was plenty of activity in Poland, Germany and the Soviet Union. The Nazis were steadily establishing their occupation of Poland by imprisoning or killing the country’s residents.

Meanwhile, the Soviet Union was pursuing war on other soil. On Nov. 30, Josef Stalin declared war on Finland but met with an even match. The fighting in Finland went on until spring, while the German forces rested from battle, exhausted from fighting in bitter winter conditions.

Later Developments: World War II

Ultimately, World War II was the bloodiest in history, with a death toll of more than 62 million. Battles were fought in Europe, the Middle East, China, Japan and Africa. Germany surrendered May 7, 1945; after the atomic bombing of Hiroshima and Nagasaki, Japan surrendered on Aug. 15, 1945.

The findingDulcinea Web Guide to World War II links to the most comprehensive and reliable sources on the war.

Leave a Reply

Your email address will not be published. Required fields are marked *

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram