- Japan declares war on Germany
- The Battle of Mons begins, a phase of the Battle of the Frontiers. The British Army attempts to secure the Mons–Condé Canal against the advancing Germans. The British were eventually forced to retreat. The Battle of Mons constitutes the first major action of the British Expeditionary Force.
- The Battle of Tannenberg starts. The fighting lasts until 30 August; the Russian army is decimated by the Germans: 92,000 Russian troops are captured, 78,000 killed or wounded. In contrast, the Germans suffer just 12,000 casualties.
- The beginning of the Battle of Lemberg. The Russians capture the Ukranian town of Lviv.
- Battle of Kraśnik, a phase of the Battle of Lemberg. The Austro-Hungarian First Army defeats the Russian Fourth Army. This is Austria-Hungary’s first victory.
Austro-Hungarian troops rest during the Battle of Krasnik. Image courtesy Wikimedia.
