Socialist Federal Republic of Yugoslavia
Regarding rivers, the Danube was navigable throughout its entire course in Yugoslavia, linking the ports of Belgrade, Novi Sad, and Vukovar with Central Europe and the Black sea. Long stretches of rivers Sava, Drava and Tisza were also navigable.
Internationalization of the Danube River
In 1616 an Austro-Turkish treaty was signed in Belgrade wherein the Austrians were granted the right to navigate the middle and lower Danube, at that time under the control of the Ottoman Empire. Under the 1774 Treaty of Küçük Kaynarca, ending a war between Russia and Turkey, Russia was allowed to use the lower Danube.