The Spanish troops set siege to Rocroi, which lay athwart the route to the Oise. The French army, under the command of Condé, was arranged with two lines of infantry in the centre, squadrons of cavalry on each wing, with a thin line of artillery at the front. The Spanish army was similarly arranged, but with its infantry in their traditional tercios. The battle began at dawn: the French infantry was worsted by the Spanish, and the cavalry on the French left was also ineffective. But the calvary on the French right wing, under the command of Gassion, routed the Spanish cavalry opposite, and Condé was able to follow this up by a huge cavalry encirclement around the entire Spanish rear. The tercios. stuck in the middle, were unable to break out and were mown down by the French artillery.