September 1 in Military History — On This Day

Invasion of Poland

Germany invaded Poland from the west on September 1st with 1.5 million troops, using Blitzkrieg — coordinated tanks, motorized infantry, and dive bombers — to shatter Polish defenses. On September 17th, the Soviet Union invaded from the east under the secret Molotov-Ribbentrop Pact. Warsaw surrendered September 27th. Poland was divided between Nazi Germany and the Soviet Union.

The battle that began WWII and demonstrated Blitzkrieg's devastating effectiveness. Britain and France declared war on Germany September 3rd but provided no meaningful military assistance to Poland. The speed of Poland's fall shocked the world — the entire country conquered in 26 days.

Full battle details →

⚔️📍 Poland1939

Germany Invades Poland — World War II Begins

Germany launched a massive invasion of Poland from three directions — using Blitzkrieg tactics combining tanks, aircraft, and motorized infantry — beginning at 4:45 a.m. without a declaration of war. The invasion followed the staged Gleiwitz false flag attack the night before.

The invasion of Poland started the most destructive conflict in human history, which would kill 70–85 million people over the next six years.

Outcome

Poland overrun in 5 weeks; WWII begins