Boundaries

Although external historical events often changed Bulgaria's national boundaries in its first century of existence, natural terrain features defined most boundaries after 1944, and no significant group of people suffered serious economic hardship because of border delineation. Postwar Bulgaria contained a large percentage of the ethnic Bulgarian people, although numerous migrations into and out of Bulgaria occurred at various times. None of the country's borders was officially disputed in 1991, although nationalist Bulgarians continue to claim that Bulgaria's share of Macedonia—which it shares with both Republic of Macedonia and Greece—is less than just because of the ethnic connection between Macedonians and Bulgarians.
Bulgaria has a total border of about 2,264 km. Rivers account for about 680 km and the Black Sea coast for 400 km; the southern and western borders are mainly defined by ridges in high terrain. The western and northern boundaries are shared with Serbia and Montenegro and Romania, respectively, and the Black Sea coastline constitutes the entire eastern border. The Romanian border follows the Danube for 464 km from the northwestern corner of the country to the city of Silistra and then cuts to the east-southeast for 136 km. The Danube, with steep bluffs on the Bulgarian side and a wide area of swamps and marshes on the Romanian side, is one of the most effective river boundaries in Europe. The line through Dobruja is arbitrary and was redrawn several times according to international treaties. In that process, most inhabitants with strong national preferences resettled in the country of their choice. Borders to the south are with Greece and Turkey, the border with Greece being 491 kilometres long, and the Turkish border having a length of 240 kilometres.