Meanwhile the war had opened vigorously in Hainault.  Louis of Nassau had no sooner found himself in possession of Mons than he had despatched Genlis to France, for those reinforcements which had been promised by royal lips.  On the other hand, Don Frederic held the city closely beleaguered; sharp combats before the walls were of almost daily occurrence, but it was obvious that Louis would be unable to maintain the position into which he had so chivalrously thrown himself unless he should soon receive important succor.  The necessary reinforcements were soon upon the way.  Genlis had made good speed with his levy, and it was soon announced that he was advancing into Hainault, with a force of Huguenots, whose numbers report magnified to ten thousand veterans.  Louis despatched an earnest message to his confederate, to use extreme caution in his approach.  Above all things, he urged him, before attempting to throw reinforcements into the city, to effect a junction with the Prince of Orange, who had already crossed the Rhine with his new army.

Genlis, full of overweening confidence, and desirous of acquiring singly the whole glory of relieving the city, disregarded this advice.  His rashness proved his ruin, and the temporary prostration of the cause of freedom.  Pushing rapidly forward across the French frontier, he arrived, towards the middle of July, within two leagues of Mons. The Spaniards were aware of his approach, and well prepared to frustrate his project.  On the 19th, he found himself upon a circular plain of about a league’s extent, surrounded with coppices and forests, and dotted with farm-houses and kitchen gardens.  Here he paused to send out a reconnoitring party.  The little detachment was, however, soon driven in, with the information that Don Frederic of Toledo, with ten thousand men, was coming instantly upon them.  The Spanish force, in reality, numbered four thousand infantry, and fifteen hundred cavalry; but three thousand half-armed boors had been engaged by Don Frederic, to swell his apparent force.  The demonstration produced its effect, and no sooner had the first panic of the intelligence been spread, than Noircarmes came charging upon them at the head of his cavalry.  The infantry arrived directly afterwards, and the Huguenots were routed almost as soon as seen.  It was a meeting rather than a battle.  The slaughter of the French was very great, while but an insignificant number of the Spaniards fell.  Chiappin Vitelli was the hero of the day.  It was to his masterly arrangements before the combat, and to his animated exertions upon the field, that the victory was owing.  Having been severely wounded in the thigh but a few days previously, he caused himself to be carried upon a litter in a recumbent position in front of his troops, and was everywhere seen, encouraging their exertions, and exposing himself, crippled as he was, to the whole brunt of the battle.  To him the victory nearly proved fatal; to Don Frederic it brought increased renown.  Vitelli’s exertions, in his precarious condition, brought on severe inflammation, under which he nearly succumbed, while the son of Alva reaped extensive fame from the total overthrow of the veteran Huguenots, due rather to his lieutenant and to Julian Romero.