Italian soldiers praying on Mount Ortigara, Italy, 1917. Image in public domain.
- The Italian Sixth Army attacks the 11th Austro-Hungarian Army on the southern front near Trentino in an attempt to capture Mount Ortigara, in the Asiago Plateau. The Battle of Ortigara continues for two weeks; the Italians are repelled with flamethrowers and gas, sustaining some 25,000 casualties, including 2,800 dead. Some Italian battalions lose more than 70% of their effective strength Austria suffers 9,000 casualties.
- Fighting continues in the Battle of Messines on the Western Front; Allied troops continue to gain ground
