The Duke de Montmorency and the Maréchal Schomberg joined their army about four or five days after, and immediately, according to the cardinal's instructions, put themselves on the march for the relief of Casale.
The army had marched over a great plain, with some marshy grounds on the right and the Po on the left, and as the country was so well discovered that 'twas thought impossible any mischief should happen, the generals observed the less caution. At the end of this plain was a long wood and a lane or narrow defile through the middle of it.
Through this pass the army was to march, and the van began to file through it about four o'clock. By three hours' time all the army was got through, or into the pass, and the artillery was just entered when the Duke of Savoy with 4000 horse and 1500 dragoons with every horseman a footman behind him, whether he had swam the Po or passed it above at a bridge, and made a long march after, was not examined, but he came boldly up the plain and charged our rear with a great deal of fury.
Our artillery was in the lane, and as it was impossible to turn them about and make way for the army, so the rear was obliged to support themselves and maintain the fight for above an hour and a half.
In this time we lost abundance of men, and if it had not been for two accidents all that line had been cut off. One was, that the wood was so near that those regiments which were disordered presently sheltered themselves in the wood; the other was, that by this time the Maréchal Schomberg, with the horse of the van, began to get back through the lane, and to make good the ground from whence the other had been beaten, till at last by this means it came to almost a pitched battle.
There were two regiments of French dragoons who did excellent service in this action, and maintained their ground till they were almost all killed.
Had the Duke of Savoy contented himself with the defeat of five regiments on the right, which he quite broke and drove into the wood, and with the slaughter and havoc which he had made among the rest, he had come off with honour, and might have called it a victory; but endeavouring to break the whole party and carry off some cannon, the obstinate resistance of these few dragoons lost him his advantages, and held him in play till so many fresh troops got through the pass again as made us too strong for him, and had not night parted them he had been entirely defeated.
At last, finding our troops increase and spread themselves on his flank, he retired and gave over. We had no great stomach to pursue him neither, though some horse were ordered to follow a little way.
The duke lost about a thousand men, and we almost twice as many, and but for those dragoons had lost the whole rear-guard and half our cannon. I was in a very sorry case in this action too. I was with the rear in the regiment of horse of Perigoort, with a captain of which regiment I had contracted some acquaintance. I would have rid off at first, as the captain desired me, but there was no doing it, for the cannon was in the lane, and the horse and dragoons of the van eagerly pressing back through the lane must have run me down or carried me with them. As for the wood, it was a good shelter to save one's life, but was so thick there was no passing it on horseback.
Our regiment was one of the first that was broke, and being all in confusion, with the Duke of Savoy's men at our heels, away we ran into the wood. Never was there so much disorder among a parcel of runaways as when we came to this wood; it was so exceeding bushy and thick at the bottom there was no entering it, and a volley of small shot from a regiment of Savoy's dragoons poured in upon us at our breaking into the wood made terrible work among our horses.