Bad roads and freezing rain had slowed the Austrian advance in the first week, but the opposing Bavarian forces have gradually retreated.

The Austrian attack occurs about a week before Napoleon's anticipations, and in his absence Berthier's role becomes all the more critical.

Berthier (whose fortè is staff work) proves to be an insufficient field commander, a characteristic made worse by the fact that several messages from Paris had been being delayed and misinterpreted when they finally arrived at headquarters.

Whereas Napoleon had written to Berthier that an Austrian attack before April 15 should be met by a general French concentration around Donauwörth and Augsburg, Berthier had focused on a sentence that called for Davout to station his III Corps around Regensburg and had ordered the Iron Marshal to move back to the city despite massive Austrian pressure.