France entered World War I when Germany declared war on 3 August 1914.
German troops parade down the Champs-Élysées in Paris after their victory in the Franco-Prussian War
Poincaré elected president in 1913.
A French propaganda poster from 1917 portrays Prussia as an octopus stretching out its tentacles vying for control. It is captioned with an 18th-century quote: "Even in 1788, Mirabeau was saying that War is the National Industry of Prussia."
The Russian Empire's entry into World War I unfolded gradually in the days leading up to July 28, 1914. The sequence of events began with Austria-Hungary's declaration of war on Serbia, a Russian ally. In response, Russia issued an ultimatum to Vienna via Saint Petersburg, warning Austria-Hungary against attacking Serbia. As the conflict escalated with the invasion of Serbia, Russia commenced mobilizing its reserve army along the border of Austria-Hungary. Consequently, on July 31, Germany demanded that Russia demobilize. When Russia did not comply, Germany declared war on Russia on August 1, 1914. According to its war plan, Germany prioritized its offensive against France, declaring war on August 3. Germany deployed its main armies through Belgium with the aim of encircling Paris. The imminent threat to Belgium prompted Britain to declare war on Germany on August 4. The Ottoman Empire subsequently joined the Central Powers and engaged in warfare against Russia along their shared border.
Russian troops in the trenches at the East Prussian frontier.
A Russian recruiting poster. Caption reads: "World on Fire; Second Patriotic War."
Nicky (Tsar Nicholas II) (right) with Willy (Kaiser Wilhelm) in 1905. Nicholas is wearing a German Army uniform, and Wilhelm is wearing that of a Russian hussar regiment.
Russian prisoners at the Battle of Tannenberg where German forces annihilated the Russian Second Army.