A declaration of war against Germany.
The invasion of Poland on 1 September 1939 was followed by a declaration of war against Germany by Britain and France two days later.
Germany against United Kingdom, France and Belgium.
Britain and France declared war on Germany on 3 September 1939 following the German attack on Poland two days earlier.
Britain and France had a defence pact with Poland. When German forces attacked Poland on 1st September 1939, Britain and France demanded that they withdraw. Germany ignored the request, so on 3rd September 1939 Britain and France issued a joint declaration of war against Germany.
The United Kingdom fought against the German Empire in the Battle of Cambrai.
The United Kingdom, Germany, France, the Kingdom of the Netherlands, and several others more.
The German invasion of Poland on 1 September followed by the joint declaration of war against Germany by Britain and France on 3 September.
France's reason for seeking revenge against Germany was a result of the Franco-Prussian war. France lost and Germany took some of their land.
In the usual way - by issuing a declaration of war.
germany france united kingdom
Belgium United Kingdom France Germany Italy Portugal Spain