The river that begins at the confluence of the Brigach and Breg in Germany is the Danube.
The two headstreams meet in Donaueschingen, in Baden-Württemberg’s Black Forest. From that confluence onward, the river is called the Danube; the Breg is the longer headstream and rises near Furtwangen. A symbolic source is also associated with the Donaubach spring in Donaueschingen, which feeds the Brigach, so references may distinguish between the hydrographic source and the named river’s beginning.
From Germany, the Danube flows southeast for about 2,730 kilometers before reaching the Black Sea through the Danube Delta. It passes through or along 10 countries and crosses four national capitals: Vienna, Bratislava, Budapest and Belgrade.
A common mix-up is the Main, which joins the Rhine–Main–Danube Canal and helps form a navigable route between the North Sea and Black Sea. The Elbe and Rhine are separate major European rivers, not headstreams of the Danube.