Geography of Croatia - Area and Borders

Area and Borders

Croatia's territory covers 56,594 square kilometres (21,851 square miles), making it the 127th largest country in the world. The physical geography of Croatia is defined by its location—it is described as a part of Central Europe and Southeast Europe, a part of the Balkans and Mitteleuropa. Croatia borders Bosnia–Herzegovina and Serbia in the east, Slovenia in the west, Hungary in the north and Montenegro and the Adriatic Sea in the south. It lies mostly between latitudes 42° and 47° N and longitudes 13° and 20° E. Part of the extreme south of Croatia is separated from the rest of the mainland by a short coastline strip around Neum belonging to Bosnia–Herzegovina.

Croatia's 355.5-kilometre (220.9 mi) border with Hungary was inherited from Yugoslavia. Much of the border with Hungary follows the Drava River or its former river bed; that part of the border dates from the Middle Ages. The border in Međimurje and Baranya was defined as a border between the Kingdom of Hungary and the Kingdom of Serbs, Croats, and Slovenes, later renamed the Kingdom of Yugoslavia, pursuant to the Treaty of Trianon of 1920. The present outline of the 1,011.4-kilometre (628.5 mi) border with Bosnia–Herzegovina and 22.6-kilometre (14.0 mi) border with Montenegro is largely the result of the Ottoman conquest and subsequent recapture of territories in the Great Turkish War of 1667–1698 formally ending with the Treaty of Karlowitz, as well as the Fifth and Seventh Ottoman–Venetian Wars. This border had minor modifications in 1947 when all borders of the former Yugoslav constituent republics were defined by demarcation commissions implementing the AVNOJ decisions of 1943 and 1945 regarding the federal organisation of Yugoslavia. The commissions also defined Baranya and Međimurje as Croatian territories, and moreover set up the present-day 317.6-kilometre (197.3 mi) border between Serbia and Croatia in Syrmia and along the Danube River between Ilok and the Drava river's mouth and further north to the Hungarian border; the Ilok/Drava section matched the border between the Kingdom of Croatia-Slavonia and Bács-Bodrog County that existed until 1918 (the end of World War I). Most of the 667.8-kilometre (415.0 mi) border with Slovenia was also defined by the commissions, matching the northwestern border of the Kingdom of Croatia-Slavonia, and establishing a new section of Croatian border north of the Istrian peninsula according to the ethnic composition of the territory previously belonging to the Kingdom of Italy.

Pursuant to the 1947 Treaty of Peace with Italy the islands of Cres, Lastovo and Palagruža and the cities of Zadar and Rijeka and most of Istria went to communist Yugoslavia and Croatia, while carving out the Free Territory of Trieste (FTT) as a city-state. The FTT was partitioned in 1954 as Trieste itself and the area to the north of it were placed under Italian control, and the rest under Yugoslav control. The arrangement was made permanent by the Treaty of Osimo in 1975. The former FTT's Yugoslav part was partitioned between Croatia and Slovenia, largely conforming to the area population's ethnic composition.

In the late 19th century, Austria-Hungary established a geodetic network, for which the elevation benchmark was determined by the Adriatic Sea's average level at the Sartorio pier in Trieste. This benchmark was subsequently retained by Austria, adopted by Yugoslavia, and kept by the states that emerged after its dissolution, including Croatia.