In the mean time there had been much alarm in Brussels.  Egmont, who omitted no opportunity of manifesting his loyalty, offered to throw himself at once into the Isle of Walcheren, for the purpose of dislodging any rebels who might have effected an entrance.  He collected accordingly seven or eight hundred Walloon veterans, at his disposal in Flanders, in the little port of Sas de Ghent, prepared at once to execute his intention, “worthy,” says a Catholic writer, “of his well-known courage and magnanimity.”  The Duchess expressed gratitude for the Count’s devotion and loyalty, but his services in the sequel proved unnecessary.  The rebels, several boat-loads of whom had been cruising about in the neighborhood of Flushing during the early part of March, had been refused admittance into any of the ports on the island.  They therefore sailed up the Scheld, and landed at a little village called Ostrawell, at the distance of somewhat more than a mile from Antwerp.

The commander of the expedition was Marnix of Tholouse, brother to Marnix of Saint Aldegonde.  This young nobleman, who had left college to fight for the cause of religious liberty, was possessed of fine talents and accomplishments.  Like his illustrious brother, he was already a sincere convert to the doctrines of the reformed Church.  He had nothing, however, but courage to recommend him as a leader in a military expedition.  He was a mere boy, utterly without experience in the field.  His troops were raw levies, vagabonds and outlaws.

Such as it was, however, his army was soon posted at Ostrawell in a convenient position, and with considerable judgment.  He had the Scheld and its dykes in his rear, on his right and left the dykes and the village.  In front he threw up a breastwork and sunk a trench.  Here then was set up the standard of rebellion, and hither flocked daily many malcontents from the country round.  Within a few days three thousand men were in his camp.  On the other handy Brederode was busy in Holland, and boasted of taking the field ere long with six thousand soldiers at the very least.  Together they would march to the relief of Valenciennes, and dictate peace in Brussels.

It was obvious that this matter could not be allowed to go on.  The Duchess, with some trepidation, accepted the offer made by Philip de Lannoy, Seigneur de Beauvoir, commander of her body-guard in Brussels, to destroy this nest of rebels without delay.  Half the whole number of these soldiers was placed at his disposition, and Egmont supplied De Beauvoir with four hundred of his veteran Walloons.