 At Frastanz, a few kilometers south-east of Feldkirch, the Habsburg troops had blocked the entry to the Montafon valley with a strong wooden fortification called a "Letzi".The Swiss used a flanking maneuver to bypass the "Letzi" and after a hard battle routed Maximilian's army.Many "Landsknechte" drowned in the river Ill.

Because a frontal assault on the strong fortifications at Frastanz seemed futile, the commander of the Swiss troops, Heinrich Wolleb from Uri, devised an alternate battle plan.