It was when Germany invaded Poland.
Its invasion of poland in 1939.
Britain and France declared war on Germany on September 3, 1939. The reason was because Germany had launched a military invasion of Poland two days earlier, even though Britain and France had told Germany not to do so.
The German invasion of Poland on 1 September 1939.
As dictated by a promise made, France and Britain immediately declared war on Germany after the invasion of Poland.
During the 1930's, Britain and France had a defence agreement with Poland. On 1 September 1939, German troops invaded Poland, so on 3 September 1939, in response to that invasion, Britain and France declared war on Germany.
Britain and France on 3rd September 1939 and Poland 2 days before on 1st September
Great Britain and France declared war on Germany in 1939, because germany had invaded land that Great britain had to protect for france.
Great Britain and France declared war on Germany in 1939, because germany had invaded land that Great britain had to protect for france.
Germany's blitzkrieg against poland
1939
Britain and France declared war on Germany on September 3, 1939. The reason was because Germany had launched a military invasion of Poland two days earlier, even though Britain and France had told Germany not to do so.
By Nazi Germany invading Poland, and Britain's ally, France joining Britain in declaring war against Germany, which in turn led Japan to declare war against Britain and France, which then escalated the war from a pan European to Global (eventually).
Germany invaded Poland privacy and the allies France and Britain declared war
Britain and France had a defence agreement with Poland. On 1 September 1939, German troops invaded Poland, so on 3 September 1939, Britain and France declared war on Germany.
September 1939
France and Britain had promised to declare war if Germany tried to obtain anymore territory. And they kept that promise when Poland was invaded.
The German invasion of Poland on 1 September 1939.
Because at 1 September 1939 Germany invaded Poland.