Source of the Danube of Baden): “Danube, the biggest river of Germany, rises at the Martinskapelle in a wild and lonely area of the Black Forest, is called Brege at its origin and forms the river Danube in Donaueschingen where it is unified with the Brigach." (German original: „Donau, der größte Fluß Deutschlands, entspringt bei der Martinskapelle in einer wilden und einsamen Gegend des Schwarzwaldes, heißt am Anfang Brege… und bildet erst in Donaueschingen, wo sie sich mit der Brigach vereinigt, die Donau.“) The identification of the main spring in the uppermost Bregtal (also called Katzensteig) is dependent on a defining convention: Instead of
Source of the Danube what is the spring of the Danube also interested the oceanographer Jacques Cousteau, who in 1987 filmed a documentary about the Danube around St. Martin's Church. For centuries, the two cities Furtwangen and Donaueschingen competed for an official status which declares their own source as the official source of the Danube. The city Furtwangen is located along the upper river Breg, while the city Donaueschingen is located at the symbolic source of the Danube. At times, the issue even involves the government of Baden-Württemberg. After the city council Donaueschingen intervened in 1981, for example, the Ministry of the Interior in