Fourth Balkan War

The Fourth Balkan War was a conflict fought between Bulgaria and the joint forces of Serbia, Romania and Greece, starting in April 14th 1929 and ending in Bulgarian defeat on June 20th 1930. The aftermath of the war saw the complete collapse of the Tsardom of Bulgaria, resulting in the Bulgarian Civil War. The war was started by Serbia.

Background

Relations between Bulgaria and Serbia had been tense ever since the Second Balkan War (1913) by their conflict over the region of Vardar Macedonia.