Balkan Front (World War I)

The Balkan Front, Balkans theatre or Balkan campaign was a theatre of World War I fought between the Central Powers (Austria-Hungary, Bulgaria, Germany and the Ottoman Empire) and the Allies (Serbia, Montenegro, France, the United Kingdom, Russia, Italy, and later, Greece). The offensive began in 1914 with three failed Austro-Hungarian offensives into Serbia.

Source: Wikipedia — Balkan Front (World War I) (CC BY-SA 4.0)