After halting seven days at Madrid, the brigade moved to St. Ildefonso, where it was cantoned for a few days. Intelligence was received that the army of General Clausel, who had succeeded Marmont, was advancing on Valladolid, and the British in consequence assembled at Olivares and its vicinity. An immediate attack was intended; but the artillery of the fifth division not arriving in time, the enemy retired on the 7th of September, having destroyed the bridge at Valladolid. They continued retreating rapidly till the 17th, when the immediate vicinity of Burgos induced Clausel to make a stand, and Colonel Ponsonby's brigade was ordered to the front; but, before the army could be formed for attack, the enemy again retired to Breviesca, leaving a strong garrison in the castle of Burgos. The castle was invested, and the covering army took up a position on the heights of Quintana Palla, the KING'S OWN being at Villa Yerna. On the 19th of October, the French General Souham, who now commanded in the place of Clausel, being greatly reinforced, resolved to attempt the relief of Burgos. About four P. M. the French attacked and carried the village of Quintanapalla, but were repulsed in every attempt to penetrate farther, and abandoned the village on the approach of a force destined to retake it, consisting of the left wing of infantry, and Ponsonby's brigade of cavalry. It being ascertained that Marshal Soult and Joseph Bonaparte were moving on the Tagus, and that Sir Rowland Hill, menaced by such powerful forces, could not maintain his position on that river, at the same time his retreat would leave the army before Burgos, already in a critical situation, quite insulated, the Marquis of Wellington resolved to retire so far as was necessary to form a junction with Sir Rowland Hill; and at dusk on the 21st, the army withdrew with such celerity and silence that the French were not aware of the retreat till the British had reached Hormillas, and did not show in any force till the evening of the 22nd of October. On the next morning the retrograde movement was continued in two columns, Ponsonby's brigade covering the column from Hormillas, and being threatened during the day by an immense body of cavalry. Such was the steadiness of the troops, that the overwhelming, force of the French could make no impression and the column went into bivouac for the night on the hills above Cordovilla, with little or no loss.