Internecine conflict

By this time disputes over Ottoman territories had fractured the Balkan alliance. During the first month of the war the Serbs had occupied the greater share of Macedonia. Austro-Hungarian opposition and the creation of Albania prevented the Serbs from realising their objectives of obtaining northern Albania with its outlet on the Adriatic Sea. To compensate for this loss the Serbs indicated that they intended to remain in Macedonia in defiance of the March 1912 Treaty with Bulgaria. The Greeks had never reached an agreement with the Bulgarians over the disposition of southern Macedonia and Athens and Belgrade soon recognised a common cause against Sofia. Sporadic fighting between Bulgarian and Greek troops erupted around Nigrita in southeastern Macedonia in the spring of 1913.

In June 1913 the Russian government bungled an attempt to arbitrate the Bulgarian-Serbian dispute. As a consequence the Second Balkan War between Bulgaria and its erstwhile allies began with Bulgarian attacks on Greek and Serbian positions in Macedonia on June 30th, 1913. After initial setbacks the Bulgarians stabilised their position. However the entry into the conflict on July 10th by the Romanians, who wanted Bulgarian Dobrudzha (Dobruja), and two days later by the Ottomans, who sought to regain Adrianople, doomed the Bulgarian war effort. Beset by enemies on all sides, the Bulgarians sued for peace. They signed one treaty with Greece, Montenegro, Romania and Serbia at Bucharest on August 10th and another with the Ottoman Empire in Constantinople on September 30th. The Treaty of Athens, signed on November 14th, 1913 formally ended the conflict between Greece and the Ottoman Empire. The Serbs signed another Treaty of Constantinople on March 14th, 1914, finally concluding the war against the Ottomans.

All the Balkan states gained some territory and population from the two conflicts. Despite its defeat in the Second Balkan War Bulgaria obtained a corner of southeastern Macedonia, western Thrace (including an outlet on the Aegean Sea) and two small bits of eastern Thrace. Greece acquired most of Epirus and southern Macedonia, including the major port of Salonika. Montenegro got half of the Sanjak of Novi Pazar, Romania seized the Bulgarian part of Dobrudzha, while Serbia won most of Macedonia, Kosovo and the other half of Novi Pazar.

Yet the treaties of Athens, Bucharest and Constantinople did not end fighting in the Balkan peninsula. Serbian troops continued to skirmish with Albanian irregulars along the as yet uncertain Albanian-Serbian frontier. An Austro-Hungarian ultimatum on October 18th, 1913 demanded that the Serbs evacuate Albanian territory. The Belgrade government complied, but Albanians and Serbs continued to fight in the region, as did Albanians and Greeks in southern Albania.