Question: what were the origins and causes of the third balkan war

title: Balkan Wars
text: Though the Balkan allies had fought together against the common enemy , that was not enough to overcome their mutual rivalries . In the original document for the Balkans league , Serbia promised Bulgaria most of Macedonia . But before the first war come to an end , Serbia ( in violation of the previous agreement ) and Greece revealed their plan to keep possession of the territories that their forces had occupied . This act prompted the tsar of Bulgaria to invade his allies . The Second Balkan War broke out on 29 ( 16 ) June 1913 when Bulgaria attacked its erstwhile allies in the First Balkan War , Serbia and Greece , while Montenegro and the Ottoman Empire intervened later against Bulgaria , with Romania attacking Bulgaria from the north . When the Greek army entered Thessaloniki in the First Balkan War ahead of the Bulgarian 7th division by only a day , they were asked to allow a Bulgarian battalion to enter the city . Greece accepted in exchange for allowing a Greek unit to enter the city of Serres .