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.
Balkans
With the start of the Second World War, all Balkan countries, with the exception of Greece, were allies of Nazi Germany, having bilateral military agreements or being part of the Axis Pact. Fascist Italy expanded the war in the Balkans by using its protectorate Albania to invade Greece. After repelling the attack, the Greeks counterattacked, invading Italy-held Albania and causing Nazi Germany's intervention in the Balkans to help its ally. Days before the German invasion, a successful coup d'état in Belgrade by neutral military personnel seized power.