18 October

Western Front

 * The Yser held by the Belgians against the Germans: struggle from Lombartzyde to Keyem.
 * Roulers occupied by the Germans after fierce three-days' battle.

Eastern Front

 * Galicia: Beginning of a desperate but vain effort of the Austrians to cross the river San.

Naval and Overseas Operations

 * Belgian Coast: British monitors under Admiral Hood aid the Belgians in the Battle of the Yser.
 * Loss of British submarine E3 by U-27 announced by German wireless.