Campo Mayor surrendered before the arrival of the troops sent to its relief, and the French, having dismantled the works, were marching out of the town as the British approached it on the morning of the 25th of March,--they consisted of nearly nine hundred cavalry, three battalions of infantry, some horse artillery, and a battering train of sixteen guns, under the command of their celebrated general, Latour Maubourg. One squadron of the THIRTEENTH Dragoons was attached to the light division on this occasion; a troop was with a brigade of Portuguese infantry, and five troops were at the head of the column. Having turned the town by the left, the regiment sent forward one troop to skirmish with the enemy, who retreated by the Badajoz road. The British pressed forward in a semi-circular form, to enclose the French, who halted with their infantry in square, and their cavalry formed in their front and rear. Colonel MICHAEL HEAD was directed to attack with the two squadrons of the THIRTEENTH, amounting to two hundred and three officers and soldiers, and he led them forward with the most distinguished gallantry[4]; a regiment of French hussars advanced to meet the THIRTEENTH, and the opposing horsemen raised a loud shout and rushed upon each other. Several men were overthrown by the shock; the combatants pierced through on both sides, and facing about, charged each other again with the most heroic bravery. A sharp sword conflict ensued, in which the valour of the THIRTEENTH proved victorious, and many of the hussars having been cut down, the remainder fled. In the mean time, a French squadron formed on the enemy's right, wheeled inwards, and, attacking the British left, did some mischief; but the THIRTEENTH promptly opposed, and overthrew them after a short contest. The French continued their flight, the THIRTEENTH followed, and such was the ardour of these brave swordsmen, that the fire of the French infantry could not stop them; they galloped forward, cut down the French gunners, and, believing the other brigades would easily dispose of the French troops thus passed, they continued the pursuit. For some time the French dragoons resisted, but their formation soon became so completely broken, that they surrendered as soon as they were overtaken. The pursuit was continued at a rapid rate, the object being to gain the front, and capture the whole, as well as the enormous quantity of baggage on the road; but the dragoons were not aware of what was taking place in the rear. Marshal Beresford was informed that the THIRTEENTH Dragoons were cut off; the loss of one regiment appeared to be a serious disaster, and he did not permit the heavy cavalry to charge. The French infantry retiring steadily, recovered their artillery, and effected their retreat. Meanwhile the THIRTEENTH and some Portuguese squadrons, commanded by Colonel Otway, who formed as a support during the attack, were pursuing the French troopers at a rapid pace; on arriving at the bridge