The Balkans Campaign, also known as the Balkan Theatre or the Third Balkan War, was a theatre of conflict that occurred during World War I. The front began following the assassination of Archduke Franz Ferdinand from Austria-Hungaryball and this lead to Austria-Hungaryball and their other Central Powers allies of German Empireball and Kingdom of Bulgariaball against the Allied Powers in the Balkans, mainly the Balkan Stateballs.
The campaign started with a failed offensive into Kingdom of Serbiaball by Austria-Hungaryball which saw the Serbs push back all gains made by the Austrians. Kingdom of Montenegroball would soon join the Kingdom of Serbiaball in their war against Austria-Hungaryball. However, it was in 1915-1916 that saw Kingdom of Serbiaball invaded by both Austria-Hungaryball and Kingdom of Bulgariaball which saw Serbian troops retreat from the mainland into the lands of neutral Principality of Albaniaball and Kingdom of Greeceball.
Kingdom of Romaniaball saw a successful offensive made by Russian Empireball into Austria-Hungaryball's territory. This pressured the Romanians to declare war on Austria-Hungarybal which saw the Romanians utterly crushed by the Austro-Hungarians, forcing the Russians to deploy troops to secure whatever was left of Kingdom of Romaniaball.
Kingdom of Greeceball was torn about joining the war as the King wanted to support the Central Powers whilst the PM wanted to support the Entente. Due to this divide, tensions rose and eventually, this climaxed into a "National Schism" between monarchist Kingdom of Greeceball and the Venezeilist Provisional Government of National Defence. This led to the abdication of the Greek king (leading to a replacement) and saw the Kingdom of Greeceball declare war on the Central Powers.
1917-1918 saw the collapse of the Balkan front as the Kingdom of Bulgariaball surrendered followed by Ottomanball and finally the surrender of Austria-Hungaryball. The result of this saw the creation of Kingdom of Yugoslaviaball, the outbreak of the Turkish War of Independence and the destruction of Austria-Hungaryball and Ottomanball.