The Grande Armée d'Allemagne is now in a perilous position of two wings separated by seventy-five miles (one hundred and twenty-one kilometers) and joined together by a thin cordon of Bavarian troops.

Berthier, the French marshals, and the rank-and-file are all evidently frustrated at the seemingly pointless marches and counter marches.

On the 16th, the Austrian advance guard had beaten back the Bavarians near Landshut and had secured a good crossing place over the Isar by evening.

Napoleon finally arrives in Donauwörth on the 17th after a furious trip from Paris.

Charles congratulates himself on a successful opening to the campaign and plans to destroy Davout's and Lefebvre's isolated corps in a double-pincer maneuver.

When Napoleon realizes that significant Austrian forces are already over the Isar and are marching towards the Danube, he insists that the entire French army deploy behind the Ilm River in a bataillon carré within forty-eight hours, all in hopes of undoing Berthier's mistakes and achieving a successful concentration.

His orders are unrealistic because he underestimates the number of Austrian troops that are heading for Davout; Napoleon believes Charles only has a single corps over the Isar, but in fact, the Austrians have five corps lumbering towards Regensburg, a grand total of eighty thousand men.

Napoleon needs to do something quickly to save his left flank from collapsing.