Troops of the German 36th Reserve Infantry Regiment in deserted French artillery positions on the Chemin des Dames, May 1917. Image courtesy Imperial War Museum © IWM (Q 87862).
- Arthur Edward Neal is killed in action in the Second Battle of Bullecourt
- Severe fighting takes place on the Western Front at Bullecourt, and Chemin des Dames
- General Henri-Philippe Petain is appointed Commander-in-Chief of French Northern and North-Eastern Groups of Armies; General Ferdinand Jean Marie Foch succeeds him Chief of the French General Staff of French Ministry of War (CGS)
- British forces on the Doiran front advance south-west of Krastali; French, Serbian and Greek troops are also successful
- British and Austrian naval forces clash in the Straits of Otranto in the Adriatic Sea; fourteen British drifters are sunk
