Testimony of the Witnesses: Comments and Commentary on War - "You Have Only to Count the Prisoners, and the Dead."
This was the Reply of a Spanish officer when asked by his captors how many men had been in the Spanish Army which the French had just defeated at Rocroi, May 19, 1643.
From about 1500, the Spanish Army had been the finest in the world. Using a balance of musket and pike armed infantry, supported by artillery and light cavalry, the Spanish Army, organized into large brigades called tercios, each essentially a small army unto itself, had taken on all comers and generally come out the winner, using massed formations that rather resembled fortresses composed of pikemen and musketeers, supported by artillery reach out and strike the enemy at a distance, and cavalry to protect the relatively immobile, blocky formations from enemy horse.
But the conduct of war had been changing. During the Dutch Rebellion, the Netherlands had developed a more flexible military system, which was shortly adopted by the French. This system stressed smaller formations, still combining muskets and pike, but with greater flexibility and mobility. At Rocoi, a fortress just inside the northern border of France to which the Spanish had laid siege, a French relief army under the duc d’Enghien first essayed several cavalry charges, success on their right being matched by failure on their left. As the French right wing cavalry, under Enghien himself, pressed against the infantry of the Spanish left, the Spanish cavalry on their own right crushingly repulsed the French horse before them, only to be halted by the French reserve. Enghien reacted by taking his right-wing cavalry around the Spanish left, and then, hurling them against the center of the Spanish rear, broke through it to overrun some of the Spanish artillery and then support his own reserve against the Spanish cavalry, which scattered.
This maneuver left 18,000 Spanish infantry – still the finest in the world – unsupported against the full weight of Enghien’s army. Twice Enghien tried a frontal attack, only to be repulsed both time with great loss. At this point Enghien concentrated all the French artillery, and the Spanish guns he had captured, and began to pound the Spanish tercios. Under the bombardment, the Spanish soon began to take heavy losses, and asked for quarter. As Enghien rode forward to discuss terms, the size of his entourage was such that many of the Spanish troops though a third frontal attack was in the offing and opened fire.
Enraged at what they perceived was a violation of a flag of truce, Enghien opened up once again, and followed this with a full scale assault. The Spanish army was virtually annihilated. Although the French took some 4,000 casualties, the Spanish suffered 8,000 dead and 7,000 wounded, almost literally as the captured officer had said, “You have only to count the prisoners, and the dead,” and the price of failing to change with the times.