Germany War II in Europe. In response to Hitler's actions, two days later, on 3 September, after a British ultimatum to Germany to cease military operations was ignored, Britain and France declared war on Germany. In the spring of 1940, Germany conquered Denmark and Norway, the Netherlands, Belgium, Luxembourg, and France forcing the French government to sign an armistice after German troops occupied most of the country. The British repelled German air attacks in the Battle of Britain in the same year. In 1941, German troops invaded Yugoslavia, Greece and the Soviet Union. By 1942, Germany and other Axis powers controlled
History of France of the continent, including France, to be drawn into war within a few short weeks. Austria-Hungary declared war on Serbia in late July, triggering Russian mobilization. On 1 August both Germany and France ordered mobilization. Germany was much better prepared militarily than any of the other countries involved, including France. The German Empire, as an ally of Austria, declared war on Russia. France was allied with Russia and so was ready to commit to war against the German Empire. On 3 August Germany declared war on France, and sent its armies through neutral Belgium. Britain entered the war on 4