During the First World War, the Ottoman Empire was governed by the Party of Union and Progress. The Committee of Union and Progress had a high level of activity, especially in Macedonia, as a secret society before the power came. An important part of the community was made up of officers fighting against the commanders engaged in separatist activities in the Balkans. The formation of the Committee of Union and Progress and bringing power to the Committee of Union and Progress is developments in the Balkans. The Union and Progress took power and then carried out gang activities in the Balkans during the Balkan War. The most concrete example of this is the establishment of a state in Western Thrace. At the beginning of the First World War, the Union and Progress government first tried to get Bulgaria into the war. After Bulgaria entered the war the Ottoman State made some attempts to gain a regional advantage against Serbia and Greece. In this study, the attempts of the Ottoman State against Bulgaria in the Balkans will be examined.

Key Words: the Ottoman State, the Committee of Union and Progress, the Teşkilat-ı Mahsusa, Bulgaria, the Balkans