Bulgaria
Bulgaria occupies a portion of the eastern Balkan peninsula, bordering five countries—Greece and Turkey to the south, Macedonia and Serbia to the west, and Romania to the north. The land borders have a total length of , and the coastline has a length of . Its total area of ranks it as the world's 105th-largest country. Bulgaria's geographic coordinates are 43° N 25° E. The most notable topographical features are the Danubian Plain, the Balkan Mountains, the Thracian Plain, and the Rhodope Mountains. The southern edge of the Danubian Plain slopes upward into the foothills of the Balkans, while the Danube defines the border with Romania. The Thracian Plain is roughly triangular, beginning southeast of Sofia and broadening as it reaches the Black Sea coast.
First Balkan War
Montenegro was also considered as the smallest nation in the Balkan Peninsula, but in recent years before the war, with support from Russia, it had improved its military skills. Also, it was the only Balkan country never to be fully conquered by the Ottoman Empire. Due to Montenegro being the smallest member of the League, it didn't have much influence. Despite this, it was advantageous for Montenegro, because when the Ottoman Empire was trying to counter the actions of Serbia, Bulgaria and Greece, Montenegro had enough time for preparations which helped its successful military campaign.