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.
Balkan Wars
The Balkan Wars (, literally "the Balkan Wars" or "Balkan Faciası", meaning "the Balkan Tragedy") consisted of two conflicts that took place in the Balkan Peninsula in 1912 and 1913. Four Balkan states defeated the Ottoman Empire in the first war; one of the four, Bulgaria, suffered defeat in the second war. The Ottoman Empire lost the bulk of its territory in Europe. Austria-Hungary, although not a combatant, became relatively weaker as a much enlarged Serbia pushed for union of the South Slavic peoples. The war set the stage for the Balkan crisis of 1914 and thus served as a "prelude to the First World War".