Ratisbon had a Protestant population who were ready to open their gates.

It seemed that the opportunity for ending the war by a march upon Vienna, which had been snatched by Wallenstein from Gustavus just when it appeared in his grasp, was now open to Duke Bernhard.
But the duke was ambitious, his demands for Franconia had not yet been entirely complied with by Oxenstiern, and he saw an opportunity to obtain his own terms.

The troops under his orders were discontented, owing to the fact that their pay was many months in arrear, and private agents of the duke fomented this feeling by assuring the men that their general was with them and would back their demands.

Accordingly they refused to march further until their demands were fully satisfied.

The Scotch regiments stood apart from the movement, though they too were equally in arrear with their pay.