Who were the allies Bulgaria and Montenegro during the First Balkan War ?
The Balkan League ( , " Balkanski sŭyuz " , " Balkaniki Symmachia " , " Balkanski savez " ) was an alliance formed by a series of bilateral treaties concluded in 1912 between the Balkan states of Greece , Bulgaria , Serbia and Montenegro , and directed against the Ottoman Empire , which at the time still controlled much of the Balkan peninsula .