For six months Don John remained in Spain, and it was a half-year during which the situation in the Netherlands had been to a very large extent transformed.
The position of Orange and his followers in Holland and Zeeland in the spring of 1576 had again darkened.

In June the surrender of Zierikzee to Mondragon was a heavy blow to the patriot cause, for it gave the Spaniards a firm footing in the very heart of the Zeeland archipelago and drove a wedge between South Holland and the island of Walcheren.
This conquest was, however, destined to have important results of a very different character from what might have been expected.

The town had surrendered on favourable terms and pillage was forbidden.

Baulked of their expected booty, the Spanish troops, to whom large arrears of pay were due, mutinied.

Under their own "eletto" they marched to Aalst, where they were joined by other mutineers, and soon a large force was collected together, who lived by plunder and were a terror to the country.