Ferdinand von Spanien
In 1634 Protestant German and Swedish forces moved south and invaded Bavaria, threatening a major Habsburg ally. In response, the Austrian Habsburg commander, Ferdinand of Hungary (son of Ferdinand II, the Holy Roman Emperor) advanced west from Bohemia (today, the Czech Republic) threatening to cut across the supply lines of the Protestant armies. Consequently, the Protestant commanders quickly reversed course and headed north. They were aware that Spanish reinforcements under Ferdinand of Hungary's cousin, the Cardinal-Infante Ferdinand of Austria, were en route from their dominions in Northern Italy. The Spanish army had marched through the Stelvio Pass trying to open a new "Spanish Road", and take their Commander to his Governorship in the Spanish Low Countries.