By: HISTORY.com Editors
Britain and France declare war on Germany
On September 3, 1939, in response to Hitler’s invasion of Poland, Britain and France, both allies of the overrun nation declare war on Germany.
The first casualty of that declaration was not German—but the British ocean liner Athenia, which was sunk by a German U-30 submarine that had assumed the liner was armed and belligerent. There were more than 1,100 passengers on board, 112 of whom lost their lives. Of those, 28 were Americans, but President Roosevelt was unfazed by the tragedy, declaring that no one was to “thoughtlessly or falsely talk of America sending its armies to European fields.” The United States would remain neutral.
French Resistance
Show: WWII in HDDavid Keran's grandfather was an OSS agent working with the French Resistance during WWII and left behind films of his experiences.
As for Britain’s response, it was initially no more than the dropping of anti-Nazi propaganda leaflets—13 tons of them—over Germany. They would begin bombing German ships on September 4, suffering significant losses. They were also working under orders not to harm German civilians. The German military, of course, had no such restrictions. France would begin an offensive against Germany’s western border two weeks later. Their effort was weakened by a narrow 90-mile window leading to the German front, enclosed by the borders of Luxembourg and Belgium—both neutral countries. The Germans mined the passage, stalling the French offensive.
The Secret British Campaign to Persuade the US to Enter WWII
The campaign used fake news to shift U.S. opinion about going to war with Germany.
The campaign used fake news to shift U.S. opinion about going to war with Germany.
Also on This Day in History
Discover more of the major events, famous births, notable deaths and everything else history-making that happened on September 3rd
Related
World War II
214 videos
Behind the lines of World War II, the United States and Germany engaged in a nuclear arms race.
These photos show the chaos and courage of the 1940 evacuation, when hundreds of thousands of Allied troops escaped German forces by sea.
Victory over Japan Day ushered in peace after the devastation of World War II.
About the author
HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Christian Zapata, Cristiana Lombardo and Adrienne Donica.
Fact Check
We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.
Citation Information
- Article Title
- Britain and France declare war on Germany
- Author
- HISTORY.com Editors
- Website Name
- History
- Date Accessed
- October 29, 2026
- Publisher
- A&E Television Networks
- Last Updated
- June 30, 2025
- Original Published Date
- November 05, 2009
