25 August

Western Front

 * Retreat from Mons; rearguard action at Landrecies; Line of Le Cateau-Esnes occupied.
 * Germans take Sedan; Maubeuge invested; Mülhausen again evacuated by the French.
 * Last Namur fort silenced.

Eastern Front

 * Poland: Austrian First Army defeats Russians at Krasnik and advances towards Lyublin.

Southern Front

 * Serbia: End of First Austrian invasion; complete defeat of the Austrians with heavy losses.

Naval and Overseas Operations

 * Cameroons: Tepe occupied by the Allies.

Political

 * Austria-Hungary declares war on Japan.
 * Lord Kitchener's first speech as Secretary of State for War.