When Bonaparte endeavoured, by a sudden advance of his numerous legions, to interpose between the British and Prussian armies, and beat them in detail, the TWELFTH Light Dragoons were suddenly ordered to march, on the morning of the 16th of June, to Enghien, from whence they continued their route, a great part of the way at a trot, to _Quatre Bras_, where they arrived at sunset, at the moment when the French troops, under Marshal Ney, were withdrawing from the contest. The regiment bivouacked on the ground behind the field of battle, and furnished small piquets along the front, in communication with the infantry. On the following day, when the army made a retrograde movement, to keep up the communication with the Prussians, the TWELFTH Light Dragoons withdrew by the lower road, through the woods and open grounds, passed the river Dyle, at a deep ford, below Genappe, and took post on the left of the position, in front of the village of _Waterloo_, where they bivouacked in the open fields, and were exposed to a heavy rain during the night. On the following morning (18th June) two powerful armies confronted each other; each occupied a range of heights of easy access, and a narrow valley was between them. Both armies were confident in their leader, and, as daylight appeared, they prepared to engage in deadly conflict. The TWELFTH Light Dragoons were formed in column of squadrons, and posted in a pea-field, above Papilot, a short distance from the left of the fifth division, which formed the left of the British infantry. Soon after mid-day Count D'Erlon's corps attacked the British left, but was repulsed, on which occasion a brilliant charge was made by the Royals, Greys, and Inniskilling Dragoons. One column of the enemy, on the extreme right of the attacking force, had not been engaged, and it continued to advance. Major-General Vandeleur had proceeded, with part of his brigade, to support the Royals, Greys, and Inniskilling Dragoons, whilst re-forming after their charge; but the TWELFTH remained on the left, and Colonel Ponsonby, having authority to act discretionally, resolved, notwithstanding the inferiority of his numbers, to attack the French column with the regiment. He formed the TWELFTH in open column, cautioned the men "to be steady, and do their duty," and led them forward over ploughed ground, saturated with rain, to attack this formidable column of infantry, which was supported on the flank by lancers, and covered by the fire of artillery from a rising ground in its rear. As the French column crossed the valley between the two armies, the TWELFTH passed the hedge-row occupied by the Highlanders, and descended the rising ground on which the British line was formed, exposed to the fire of the enemy's artillery, and receiving a volley from the column of infantry, to which the slope, the regiment was descending, rendered it a conspicuous mark. As the regiment moved forward, it gradually