Between April 16 and May 6 the French made gains in the Battle of the Aisne, between Soissons and Reims.

Between May 15 and September 15 occurred an Italian offensive in which General Cadorna inflicted severe defeats on the Austrians on the Carso and Bainsizza plateaus.
The British blew up Messines Ridge, south of Ypres, June 7 and captured 7,500 German prisoners.

June 12 King Constantine of Greece was forced to abdicate and on June 29, Greece entered the war on the side of the Allies.

A mutiny in the German fleet at Wilhelmshaven and Kiel occurred July 30 and a second mutiny September 2.
August 20-24 the French recaptured high ground at Verdun, lost in 1916.
October 23-26 a French drive north of the Aisne won important positions including Malmaison fort.

The Germans retreated from the Chemin de Dames, north of the Aisne, November 2.