This map is part of a series of 19 animated maps showing the history of Europe and nations, 1918-1942.
During the First World War, Bulgaria had chosen to join forces with the German and Austro-Hungarian Empires in the hope of regaining Macedonia and Southern Dobrudja which had been allocated to Serbia and Romania, respectively, at the end of the Second Balkan War in 1913.
Launched from Thessaloniki, the Allies attacked Bulgaria during the autumn of 1918 and quickly forced Bulgaria to ask for an armistice.
Signed in November 1919, the Treaty of Neuilly made some minor changes to Bulgaria’s western border in Serbia’s favour and gave Western Thrace to Greece, thus depriving the country of its access to the Mediterranean.
Reduced in size, the Bulgarian state soon became politically unstable.
In 1923, the Greeks pushed nearly 250,000 Bulgarians out of Thrace and Macedonia.