While Berengar's armies were marching towards the Swiss and Italian borders that Austria shared with the two realms, his Navy was on a more important mission, one that Berengar had learned from the Imperial Japanese Navy in his previous life.
In Berengar's previous life, Pearl Harbor was a term that every American citizen knew by the time they were out of elementary school; it was a degree of defeat and humiliation that the United States had never suffered before on its homefront.
As such, Berengar fully intended to learn from the Pre-emptive strike the Japanese had taken against their rivals and utilize the same tactics to eradicate the fleets of his enemies. The young Austrian King who had yet to be coronated fully intended to take advantage of the time it took for the Holy Roman Emperor to receive his declaration of Independence by striking at the heart of their Naval support.