 The crisis between Denmark and the German Confederation erupted into open conflict on 1 February 1864, after the Prussian and Austrian Empires delivered an ultimatum to Denmark to cede the disputed duchies to Austro-Prussian control.At the time, the Danish fleet was far superior to the Prussian naval forces available, which allowed the Danes to blockade the German coast.To assist the Prussians, the Austrian Navy sent "Kommodore" (Commodore) Wilhelm von Tegetthoff with the screw frigates and to break the Danish blockade.