Before World War 1 France and Russia had a military alliance. This meant that each country promised to support the other in event of war. In 1914 Germany declared war on Russia. By end the?

By the end of July 1914, the following chain of events had occurred:

- July 28, 1914: Austria-Hungary declared war on Serbia, after an ultimatum it gave to Serbia mobilized Russian forces - the first military action by a country outside the direct conflict.

- July 30, 1914: In response to the Russian mobilization, Germany declared war on Russia.

- July 31, 1914: As a result of its alliance with Russia, France declared war on Germany.

Therefore, by the end of July 1914, France had declared war on Germany due to the military alliance between France and Russia.