The following spring the war recommenced, and a diversion was effected by the Duke of Lancaster, who was in command of Brittany, joining his forces with those of the King of Navarre and many of the nobles of Normandy, while King Edward crossed to Calais and kept a portion of the French army occupied there. The Black Prince, leaving the principal part of his forces under the command of the Earl of Albret to guard the territory already acquired against the attack of the French army under the Count of Armagnac, marched with two thousand picked men-at-arms and six thousand archers into Auvergne, and thence turning into Berry, marched to the gates of Bourges. The King of France was now thoroughly alarmed, and issued a general call to all his vassals to assemble on the Loire. The Prince of Wales, finding immense bodies of men closing in around him, fell back slowly, capturing and leveling to the ground the strong castle of Romorentin. The King of France was now hastening forward, accompanied by his four sons, one hundred and forty nobles with banners, twenty thousand men-at-arms, and an immense force of infantry. Vast accessions of forces joined him each day, and on the 17th of September he occupied a position between the Black Prince and Guienne. The first intimation that either the Black Prince or the King of France had of their close proximity to each other was an accidental meeting between a small foraging force of the English and three hundred French horse, under the command of the Counts of Auxerre and Joigny, the Marshal of Burgundy, and the Lord of Chatillon. The French hotly pursued the little English party, and on emerging from some low bushes found themselves in the midst of the English camp, where all were taken prisoners. From them the Black Prince learned that the King of France was within a day's march. The prince dispatched the Captal de Buch with two hundred men-at-arms to reconnoiter the force and position of the enemy, and these coming upon the rear of the French army just as they were about to enter Poitiers, dashed among them and took some prisoners. The King of France thus first learned that the enemy he was searching for was actually six miles in his rear. The Captal de Buch and his companions returned to the Black Prince, and confirmed the information obtained from the prisoners that the King of France, with an army at least eight times as strong as his own, lay between him and Poitiers.