Political map of Europe & the Mediterranean 25 September 1913 (Aftermath of the Balkan Wars): At the Treaty of Bucharest (Treaty of Bucharest (1913)), Bulgaria ceded land to Serbia, Greece, and Romania, ending the Second Balkan War between those countries. However, the treaty did not end the war between Bulgaria and the Ottoman Empire, which raged on until Ottoman support of an insurgency in Western Thrace (Provisional Government of Western Thrace) forced Bulgaria to agree to peace (Treaty of Constantinople (1913)).