- 10. Prussians defeated by Germans in Battle of Masurian Lakes.
- 18. German submarine 'blockade' of British Isles begins.
- 25. Allied fleet destroys outer forts of Dardanelles.
- 2. Allied troops land at Kum-Kale, on Asiatic side of Dardanelles.
- 10. British take Neuve Chapelle in Flanders battle.
- 22. Austrian fortress of Przmysl surrenders to Russians.
- 22. Poison gas first used by Germans in attack on Canadians at Ypres, Belgium.
- 1. American steamer Gulflight torpedoed off Scilly Isles by German submarine; 3 lives lost.
- 2. British South Africa troops under General Botha capture Otymbingue, German Southwest Africa.
- 7. Germans capture Libau, Russian Baltic port.
- 7. Lusitania, Cunard liner, sunk by German submarine off Kinsale Head, Irish coast, with loss of 1152 lives; 102 Americans.
- 23. Italy declares war on Austria-Hungary and begins invasion on a 60 mile front.
- 31. German Zeppelins bombard suburbs of London.
- 4-6. German aircraft bomb English towns.
- 15. Allied aircraft bombs Karlsruhe, Baden, in retaliation.
- 22. Lemberg recaptured by Austrians.
- 26. Montenegrins enter Scutari, Albania.
- 9. German Southwest African surrenders to British South African troops under Gen. Botha.
- 5. Warsaw captured by Germans.
- 6. Gallipoli Peninsula campaign enters a second stage with the debarkation of a new force of British troops in Suvla Bay, on the west of the peninsula.
- 8. Russians defeat German fleet of 9 battleships and 12 cruisers at entrance of Gulf of Riga.
- 19. Arabic, White Star liner, sunk by submarine off Fastnet; 44 lives lost; 2 Americans.
- 25. Brest-Litovsk, Russian fortress, captured by Austro-Germans.
- 28. Italians reach Cima Cista, north-east of Trent.
- 30. British submarine attacks Constantinople and damages the Galata Bridge.
- 31. Lutsk, Russian fortress, captured by Austrians.
- 6. Czar Nicholas of Russia assumes command of Russian armies. Grand Duke Nicholas is transferred to the Caucasus.
- 25. Allies open offensive on Western front and occupy Lens.
- 5. Franco-British force lands at Salonika and Greek ministry resigns.
- 9. Belgrade again occupied by Austro-Germans.
- 12. Edith Cavell, English nurse, shot by Germans for aiding British prisoners to escape from Belgium.
- 13. London bombarded by Zeppelins; 55 persons killed; 114 injured.
- 14. Bulgaria at war with Serbia.
- 15. Great Britain declares war on Bulgaria.
- 17. France at war with Bulgaria.
- 19. Italy and Russia at war with Bulgaria.
- 29. Briand becomes premier of France, succeeding Viviani.
- 5. Nish, Serbian war capital, captured by Bulgarians.
- 24. Serbian government transferred to Scutari, Albania.
- 4. Henry Ford, with large party of peace advocates, sails for Europe on chartered steamer Oscar II, with the object of ending the war.
- 13. Serbia in hands of enemy, Allied forces abandoning last positions and retiring across Greek frontier.
- 15. Gen. Sir Douglas Haig succeeds Field Marshal Sir John French as Commander-in-Chief of British forces in France.
- 20. Dardanelles expedition ends; British troops begin withdrawal from positions on Suvla Bay and Gallipoli Peninsula.
- 22. Henry Ford leaves his peace party at Christiania and returns to the United States.