In the opening engagements of the war, Archduke John defeated the Franco-Italian army and drove it back to the Adige River at Verona. Forced to detach substantial forces to watch Venice and other enemy-held fortresses, John found himself facing a strongly reinforced Franco-Italian army near Verona. The outnumbered Austrians led by Archduke John of Austria successfully fended off the attacks against a Franco-Italian army headed by Eugène de Beauharnais, the Viceroy of the Kingdom of Italy. in actions at San Bonifacio, Soave, and Castelcerino before retreating to the east. ion. John knew that with Napoleon advancing on Vienna, his position in Italy could be flanked by enemy forces coming from the north. He decided to retreat from Italy and defend the borders of Austria in Carinthia and Carniola. After breaking all bridges over the Alpone, John began his withdrawal in the early hours of May 1, covered by Feldmarschallleutnant Johann Maria Philipp Frimont's rear guard.