The Breg and Brigach meet around Donaueschingen to form the Danube, which runs through Central Europe to the Black Sea. Its length is given as 2,850 kilometres, or 1,770 miles. The river and the waterways around it carried goods into and out of the continent, linking strategic positions and the routes of campaigns. Its breadth made it a useful imperial frontier as well as a highway for trade. The Romanian-Bulgarian border provides an example of a river boundary, although changing river courses complicate such divisions.
Notable Point · 8:50-15:52
Danube headwaters, trade routes and European frontiers
The Danube's route from its headwaters to the Black Sea links trade and campaigning with the use of a wide river as an imperial frontier.