First Balkan War: Bulgarian forces capture Adrianople.

The First Balkan War lasted from October 1912 to May 1913 and involved actions of the Balkan League against the Ottoman Empire. The Balkan states' combined armies overcame the initially numerically inferior and strategically disadvantaged Ottoman armies, achieving rapid success.

Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey to the south, Serbia and North Macedonia to the west, and Romania to the north. It covers a territory of 110,994 square kilometres (42,855 sq mi) and is the tenth largest within the European Union and the sixteenth-largest country in Europe by area. Sofia is the nation's capital and largest city; other major cities include Burgas, Plovdiv, and Varna.

The siege of Adrianople, was fought during the First Balkan War. The siege began on 3 November 1912 and ended on 26 March 1913 with the capture of Edirne (Adrianople) by the Bulgarian 2nd Army and the Serbian 2nd Army.

Edirne, historically known as Adrianople, is a city in Turkey, in the northwestern part of the province of Edirne in Eastern Thrace. Situated 7 km (4.3 mi) from the Greek and 20 km (12 mi) from the Bulgarian borders, Edirne was the second capital city of the Ottoman Empire from the 1360s to 1453, before Constantinople became its capital.