On the morning of the 28th, the two armies maintained their respective positions; towards the middle of the day, however, the French were observed to be retiring; they set fire to the woods to conceal their movement, but the height of Busaco so commanded the whole country, that their march was distinctly seen. Lord Wellington had been extremely anxious for the arrival of the corps of militia, under Colonel Trant, upon the Sierra of Caramula, the road over which communicated from Viseu to the great road from Oporto to Coimbra, near Sardao, Bamfiela and Avelans. This was the only pass by which the positions of the Sierra of Busaco could be turned, and there were parts of it so extremely difficult, that if this corps of militia had had the necessary time to destroy the bridges, and to avail itself of the positions afforded by the ravines which intersect the road, it might have opposed a most decisive resistance to the advance of the enemy. Lord Wellington did not choose to detach any part of the force which he considered as his effective army, to execute his object in this Sierra; such a corps might be cut off from him, or might have great difficulty in rejoining him; and he was resolved never to depart from his determination, that the great contest for the possession of Portugal should be fought by his whole army, and in a position which should leave the event as little doubtful as was possible in military operations. The corps of Colonel Trant did not form a part of the force which Lord Wellington had decided to keep with him; he intended it for the defence of Oporto, to which place its retreat was not likely to be interrupted from the Sierra of Caramula; it had therefore been ordered to occupy the latter position; but Lord Wellington would not supply its absence by any other detachment. As soon as Lord Wellington perceived the retreat of the enemy, he suspected that his object was to pass by the road just described. Colonel Trant had arrived upon the Vouga, late on the 28th; Lord Wellington was already aware, that a considerable corps of the enemy was by that time in possession of the Sierra; he therefore gave up the hope of seeing it occupied, and in the same night withdrew his whole army from Busaco, moving with his own corps into Coimbra, and directing Lieut.-General Hill to move by Thomar to Santarem. The cavalry was placed in observation of the enemy, and was directed to cover Lord Wellington’s movement to the rear. Colonel Trant was ordered to post his corps along the north bank of the Vouga; and a part of the militia from Lamego was ordered to enter Viseu in the enemy’s rear.