In the following year Spinola with two armies attempted to force the lines of the Waal and the Yssel, but, though thwarted in this aim by the wariness of the stadholder and by a very wet season, he succeeded in taking the important fortresses of Groll and Rheinberg.

Maurice made no serious effort to relieve them, and his inactivity caused much discontent and adverse comment.

His military reputation suffered, while that of his opponent was enhanced.

But subsequent events showed that Maurice, though perhaps erring on the side of caution, had acted rightly.

The armies which had threatened the safety of the Provinces had been raised at the charges of a private individual, but the financial resources, even of a Spinola, were not capable of a prolonged effort; there was no money in the State treasury; and the soldiery, as soon as their pay was in arrears, began once more to be mutinous.