On September 3, 1939, Great Britain officially declared war on Nazi Germany, marking its entry into World War II. This pivotal moment followed Germany's invasion of Poland two days prior.
Britain Enters the War
At 11:15 AM on Sunday, September 3, 1939, British Prime Minister Neville Chamberlain delivered a somber 5-minute broadcast on the Home Service. He announced that as Adolf Hitler had failed to respond to British demands to withdraw his forces from Poland, "This country is at war with Germany." This declaration came after Britain's ultimatum to Germany expired at 11:00 AM that day.
Key Events Leading to the Declaration
The declaration by Britain was the culmination of escalating tensions and broken agreements.
- September 1, 1939: Germany launched a full-scale invasion of Poland, utilizing its "Blitzkrieg" (lightning war) tactics. This unprovoked aggression directly violated international treaties and immediately prompted responses from the Western Allies.
- September 1, 1939: Britain and France issued ultimatums to Germany, demanding the withdrawal of its troops from Poland.
- September 3, 1939 (Morning): With no response from Germany, the British ultimatum expired.
- September 3, 1939 (11:15 AM): Prime Minister Chamberlain made the historic announcement that Britain was at war.
- September 3, 1939 (Later in the day): France, also bound by treaty to Poland, followed suit and declared war on Germany.
Significance of the Day
The events of September 3, 1939, were immensely significant:
- End of Appeasement: It signaled the definitive end of the policy of appeasement that Britain and France had pursued in the 1930s to avoid conflict with Nazi Germany.
- Global Conflict: While local conflicts had occurred earlier, this day marked the transformation of the European crisis into a true global war, drawing in major world powers.
- Public Awareness: Chamberlain's broadcast brought the reality of war directly into British homes, changing the lives of millions overnight.
Key Declarations on September 3, 1939
The table below summarizes the critical declarations that occurred on this day, formally igniting the wider conflict.
| Nation | Action | Time (BST) | Reason |
|---|---|---|---|
| Great Britain | Declared war on Germany | 11:15 AM | Germany's failure to withdraw from Poland |
| France | Declared war on Germany | 5:00 PM | Germany's failure to withdraw from Poland |
For more detailed information on Prime Minister Chamberlain's historic announcement, you can refer to historical archives, such as the BBC's account of the event: Chamberlain announces Britain is at war with Germany.
