Frederick had a very low opinion of his counterpart, saying of Prince Charles Alexander that "there will be some stupid mistakes." In fact, Frederick was counting on Charles entering Silesia by crossing the Riesengebirge (engl. "Giant Mountains"). If he did, Frederick intended to attack the Austrian army and crush it in one decisive blow. Hans Joachim von Zieten's Zieten-Hussars shadowed the Austrian army, keeping Frederick informed of their movements and position as he awaited the right moment to strike. When the Prince finally did cross in early June, Frederick saw his opportunity to attack.