List of tributaries of the Danube
The Danube is Europe's second-longest river. It starts in the Black Forest in Germany as two smaller rivers—the Brigach and the Breg—which join at Donaueschingen, and it is from here that it is known as the Danube, flowing generally eastwards for a distance of some , passing through several Central and Eastern European capitals, before emptying into the Black Sea via the Danube Delta in Romania.
Battle of Neuburg (1800)
The French war goal, to occupy Vienna and force the Habsburgs to accept and comply with peace terms established in 1798, required a double-pronged invasion through northern Italy, which First Consul Napoleon commanded, and through southern Germany, a campaign that fell to Moreau. To secure access into Bavaria and, eventually, to Vienna, the French needed to control the Danube riverway. This was not a new tactic: The stretch of river between Ulm and Neuburg had been the site of major battles of the Thirty Years' War and War of the Spanish Succession. Between Ulm and Ingolstadt, the Danube grows significantly in volume, making it a wide and swift waterway. The Iller joins the Danube at Ulm, dumping massive amounts of water into the stream; at Donauwörth, the Lech enters the Danube. Neuburg, the first significant city on the river after Donauwörth, had been the family seat of the princes of Pfalz-Neuburg; taking it from a princely family of the Holy Roman Empire would be a blow to the morale and prestige of the Habsburgs, whose role it was to protect the small princely domains. Control of the bridges and passages between Ulm and Donauwörth, Neuburg, then Ingolstadt offered an advantage of both transport and prestige.