On This Day - 23 May 1915
Theatre definitions: Western Front comprises the Franco-German-Belgian front and any military action in Great Britain, Switzerland, Scandinavia and Holland. Eastern Front comprises the German-Russian, Austro-Russian and Austro-Romanian fronts. Southern Front comprises the Austro-Italian and Balkan (including Bulgaro-Romanian) fronts, and Dardanelles. Asiatic and Egyptian Theatres comprises Egypt, Tripoli, the Sudan, Asia Minor (including Transcaucasia), Arabia, Mesopotamia, Syria, Persia, Afghanistan, Turkestan, China, India, etc. Naval and Overseas Operations comprises operations on the seas (except where carried out in combination with troops on land) and in Colonial and Overseas theatres, America, etc. Political, etc. comprises political and internal events in all countries, including Notes, speeches, diplomatic, financial, economic and domestic matters. Source: Chronology of the War (1914-18, London; copyright expired)
Battle of Festubert: German attack repulsed.
Austrian attack in the Carnic Alps.
Naval and Overseas Operations
Submarine E11 sinks a gunboat in the Sea of Marmora.
Italy declares war against Austria.
Italian Note to the ministers of Italy in foreign countries on the denunciation of the Triple Alliance.
Allies warn Turkey on question of Armenian massacres.