Danube
Classified as an international waterway, it originates in the town of Donaueschingen, in the Black Forest of Germany, at the confluence of the rivers Brigach and Breg. The Danube then flows southeast for about , passing through four capital cities (Vienna, Bratislava, Budapest and Belgrade) before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.
Internationalization of the Danube River
On December 28, 1854, during the Crimean War (France, Britain, Sardinia, and Turkey versus the Russian Empire), the allies sent to Russia a note urging the internationalization of the river as one of the bases for a peace treaty:
. . . it would be desirable that the course of the Lower Danube . . . be withdrawn from the territorial jurisdiction. . . . In every case the free navigation of the Danube could not be secured if it be not placed under the control of a syndical authority, invested with the powers necessary to destroy the obstructions existing at the mouths of the river, or which may hereafter be formed there.