In the Spring of 1809, the Austrian army, buoyant and full of new-found patriotic fervour, rolled across the frontier with Bavaria. The time had come to exact revenge for the humiliating defeat suffered four years earlier at Austerlitz. But ten days later, with their earlier determination washed away by the ceaseless rain, they were streaming back from the Abens river with Napoleon in hot pursuit. Napoleon had not been in the front line when Austria had launched its campaign. Under the control of Marshal Berthier the French troops and their German allies had blundered backwards and forwards across the Bavarian countryside. But with the appearance of Napoleon order was created where none had existed before and almost immediately Archduke Charles, commander of the Austrians, lost the initiative. Although defeated at Eggm"uhl on 21 April, the Austrian army, remained intact and capable of action.