 The loss of Lingen led to serious disquiet in the Dutch headquarters, and Prince Maurice had to opt for a defensive strategy.He marched to the towns threatened by Spinola with 12,000 to 13,000 men on 30 August, posting garrisons with total strength of 8,100 men,\ in Deventer, Zutphen, Zwolle, Rheinberg, Bredevoort and Groenlo.In mid-September Spinola fell back to the Rhine, crossing river, and took Mülheim an der Ruhr.