Bulgarian officers' brotherhoods, known also as Bulgarian liberation fraternities, was a clandestine military organization created at the end of the 19th century in Bulgarian army with the aim of drawing Bulgaria into a war with the Ottoman Empire. Their ultimate goal was the freedom of the territory of Macedonia and Adrianople Thrace. The brotherhoods played a significant role in the Macedonian-Adrianopolitan revolutionary movement until the beginning of the Balkan Wars.