Alva was aware of his
presence in Hainault, had captured by surprise Valenciennes and Mons
(May 24). It was a rash move, for no sooner did the news reach the
governor-general than he sent his son, Don Frederick of Toledo, at the
head of a powerful force to expel the invader. Don Frederick quickly
made himself master of Valenciennes and then proceeded (June 3) to lay
siege to Mons, where Lewis, in hopes that relief would reach him,
prepared for an obstinate defence. These hopes were not without
foundation, for he knew that, beyond the Rhine, Orange with a
considerable army was on the point of entering the Netherlands from the
east, and that the Huguenot leader, Genlis, was leading another force
from France to his succour. William at the head of 20,000 German and
3000 Walloon mercenaries actually entered Gelderland (July 7), captured
Roeremonde and then marched into Brabant. Here (July 19) the news
reached him of the complete defeat and annihilation of the raw levies of
Genlis by Toledo's veteran troops. Hampered by lack of funds William
now, as throughout his life, showed himself to be lacking in the higher
qualities of military leadership. With an ill-paid mercenary force time
was a factor of primary importance, nevertheless the prince made no
effort to move from his encampment near Roeremonde for some five weeks.
Meanwhile his troops got out of hand and committed many excesses, and
when, on August 27, he set out once more to march westwards, he found to
his disappointment that there was no popular rising in his favour.
Louvain and Brussels shut their gates, and though Mechlin, Termonde and
a few other places surrendered, the prince saw only too plainly that his
advance into Flanders would not bring about the relief of Mons. All his
plans had gone awry. Alva could not be induced to withdraw any portion
of the army that was closely blockading Mons, but contented himself in
following Orange with a force under his own command while avoiding a
general action. And then like a thunderclap, September 5, the news of
the massacre of St Bartholomew was brought to the prince, and he knew
that the promise of Coligny to conduct 12,000 arquebusiers to the
succour of Lewis could not be redeemed. In this emergency William saw
that he must himself endeavour to raise the siege. He accordingly
marched from Flanders and, September 11, encamped at the village of
Harmignies, a short distance from Mons. In the night six hundred
Spaniards, each