 As winter broke in 1799, on 1 March, General Jean-Baptiste Jourdan and his army of 25,000, the so-called Army of the Danube, crossed the Rhine at Kehl.Instructed to block the Austrians from access to the Swiss alpine passes, the Army of the Danube would ostensibly isolate the armies of the Coalition in Germany from allies in northern Italy, and prevent them from assisting one another; furthermore, if the French held the interior passes in Switzerland, they could use the routes to move their own forces between the two theaters.The Army of the Danube, meeting little resistance, advanced through the Black Forest in three columns, through the Höllental (Hölle valley), via Oberkirch, and Freudenstadt, and a fourth column advanced along the north shore of the Rhine.