The Battle of Krivolak

After Bulgaria entered the First World War on 1 October 1915 and advanced against Serbia, the First Bulgarian Army defeated Serbian troops in the Niš Operation, and the Second Army did so in the Ovche Pole Operation. Meanwhile, Entente units landed in Thessaloniki in early October and marched north to join Serbian troops that had withdrawn into Kosovo.
The advance of the French 57th and 156th Divisions was met by the southern group of the Second Bulgarian Army, comprising units from the 2nd Thracian, 5th Danube, 7th Rila and 11th Macedonian Divisions. The fighting fluctuated, with enormous losses on both sides and the 11th Division bearing the main burden on the Bulgarian side. Ultimately, despite their numerical superiority, the French withdrew into Greek territory.

The battle caused enormous casualties on all sides. Ultimately, the French divisions withdrew.