Massena commenced his march into Portugal upon the 16th of September; his army advanced in three corps; the 8th corps under Junot, moved by Pinhel upon Trancoso, the 6th corps under Ney, upon Alverca; and the 2d corps, under Regnier, upon Guarda; the British cavalry retired to Celorico. The next day the two latter corps moved into Celorico; from which place they were observed to take the road to Fornos. As soon as Lord Wellington was persuaded that the enemy had made choice of that road, and that no part of their army was moving upon the road by the Tagus, he sent directions to Lieutenant General Hill to break up from Sarzedas, and to move by Pedragoa Grande, to the Puente de Marcella; he moved the corps of Major General Leith to the same place from Thomar, and he withdrew his own divisions with the view of collecting the whole army upon the Sierra of Busaco.

Marshal Massena had commenced his operations with the hopes of turning the left of Lord Wellington, and of reaching Coimbra before the British army could be collected to oppose him; he had been induced to believe that Lord Wellington had prepared to meet him at the Puente de Marcella; but he hoped that by this movement on the right of the Mondego, he should turn that position, and find Lord Wellington unprepared to assemble in any other. He was miserably deceived; Lord Wellington was aware of the nature of the roads the enemy had fixed upon for his movements; he calculated the delays he would meet with, and arranged his plans accordingly. He directed a portion of the militia that was at Lamego under the orders of Colonel Trant to march upon Sardao; the rest was directed to move upon Trancoso and Celorico, upon the rear of the enemy, to intercept their communication with Almeida.

Marshal Massena arrived at Viseu upon the 19th of September; his artillery had suffered so much from the badness of the roads that he was obliged to remain there for some days to repair it. General Junot joined him at this place from Trancoso, so that the whole French army was collected there. On the 23d the advanced patroles of the British and French armies met each other near St. Comba de Dao. The bridge over the Cris, by which the great road to Coimbra passes, was blown up; but the following day the French advanced guard passed that river, and the greatest part of the British retired to the heights of Busaco, where the whole army was collecting. On the 25th Marshal Massena joined his advanced guard, and on the 26th pushed forward to the foot of the position which was occupied by Lord Wellington.

The ridge of heights upon which the British army was posted runs nearly north and south, from a point about four miles to the north of Busaco, to the confluence of the river Alva and the Mondego; the extreme points are nearly fifteen miles distant. Two great roads to Coimbra cross over this Sierra, the one close to the convent of Busaco, the other four miles to the southward of it, at St. Antonio de Cantaro. The corps of Lieutenant General Hill which had made a most rapid though difficult march from Sarzedas, arrived upon the Mondego on the evening of the 26th, and was directed to move into the right of the position of Busaco early on the following morning. Lord Wellington had made a road along the heights, by which his flanks communicated, and in this situation he awaited the attack of the enemy.

We may be allowed for a moment to consider the brilliancy of the movement by which the allied army had thus been collected. Massena conceived that he should surprise his antagonist by the rapidity of his march upon his flank; the British officers generally thought that it would be impossible to oppose him before he had possessed himself of Coimbra; and the corps of Lieutenant General Hill was universally thought to be totally beyond the reach of the army of Lord Wellington. Marshal Massena for a long time disbelieved the fact of its junction at Busaco; and after he had been convinced of it, denied the possibility of its having marched from Sarzedas. Yet Lord Wellington, in spite of the difficulties opposed to him, of the able movements intended to surprise him, and of the triumphant predictions of his adversary, collected his force from situations in which it seemed totally divided from him, and was prepared to fight the enemy with the whole strength of the allied army, without having lost a single man in the attainment of his object. The corps of militia under Colonel Trant, which had been ordered to Sardao, from whence it was to have moved into the Sierra of Caramula, was the only one which had not reached the ground assigned to it; this failure was occasioned by some false information as to the possession of a pass by the enemy, which obliged that corps to move by a circuitous road through Oporto. It arrived upon the Vouga on the 28th, but too late to effect the object for which it was intended.

On the morning of the 27th of September the whole French army was arrayed in front of the British position, from whence every part of it was distinctly to be seen. The corps of Marshal Ney was formed in close columns at the foot of the hill opposite the convent of Busaco. The corps of General Regnier was opposite the third division of British under Major General Picton, and prepared to advance by the road to Coimbra, which passed over the height by St. Antonio de Cantaro. The corps of General Junot was in reserve with the greater part of the cavalry, and was posted upon some rising ground about a league in the rear of Marshal Ney.

The battle commenced by a fire from the light troops of both armies, in advance of the position which was occupied by the allies; a detachment from the corps of Marshal Ney next made an attack upon a village in front of the light division, which was ceded with little opposition; this village, although of importance to the allied army, was without the position in which Lord Wellington had determined to receive the enemy’s attack; he therefore abandoned it, choosing rather to suffer some annoyance from its possession by the enemy, than risk the chance of an action to maintain it, in less advantageous ground than the position he had fixed upon. Marshal Massena was now convinced that he must fight Lord Wellington upon his own ground; he therefore directed General Regnier to advance to the assault of the position in his front, while the 1st division of Marshal Ney’s corps, supported by the other two, and a great proportion of artillery, was ordered to establish itself upon the heights occupied by the light division. General Regnier first brought his corps into action; the British regiments opposed to him had not reached the positions that were assigned to them; and, for a moment, a considerable column of French possessed itself of a point within our line. Major General Picton instantly marched against this column with a few companies which he had collected; Major General Lightburne’s brigade, directed by Lord Wellington, moved upon its right, while the 88th, 45th, and Colonel Douglass’s Regiment of Portuguese, attempted to gain its left; the troops with Major General Picton, however, first dislodged the enemy by a most brilliant attack with the bayonet, driving him, though infinitely superior in numbers, from the strong ground he had got possession of; the other regiments came up in time to harass him in his retreat; and the arrival of Major General Leith’s division, which took place at this moment, convinced General Regnier that he had better discontinue a contest, in which he had so little prospect of success. He withdrew his divisions, therefore, and formed upon the ground from which he had originally moved. During this attack, Marshal Ney formed a part of his corps in column of mass, and directed it to ascend the height upon the right of the village, of which he had before obtained possession. The ground was extremely steep, and the column was but little annoyed in its ascent; as soon, however, as it had gained the summit, the guns attached to the light division opened a most destructive fire upon it, and the division charged it with the bayonet. The column was overthrown in an instant; the riflemen charged its flanks while Major General Crawford pursued it down the hill; the foremost regiments of the column were almost totally destroyed, General Simon wounded and taken and the whole division completely routed. The expression of a French soldier engaged in this attack, who was afterwards taken, “Qu’il se laissa rouler du haut en bas de la montagne, sans savoir comment il échappa,” best explains the mode in which the remnants of this column escaped. The allies pursued it across the valley, and thus put an end to the sanguine expectations of the enemy, and to their boasted promise, of driving us like sheep from our position. The rest of the day was occupied by an incessant fire between the light troops of the two armies; Marshal Massena had placed a considerable number of battalions in the road, which extended along the ravine, at the foot of the ridge on which we were formed; and he had hoped to induce Lord Wellington to reinforce the troops that were engaged with these battalions, and by that means to get him into an action of some consequence, out of the position which he occupied. This system had frequently been successful to the French; the commanders who have been opposed to them have been unwilling to allow their too near approach to their army, and have continued to reinforce the advanced posts, till the greater part of their troops had been drawn into an action, away from the ground on which they had decided to accept a battle; but Lord Wellington was not thus to be imposed upon; he directed the light troops, when pressed, to retire, and to give the enemy an opportunity of attacking his position, if he could persuade himself to do so. At the approach of night, Marshal Massena having lost all hopes of succeeding against the allies, withdrew his troops from the advanced positions he occupied, and placed them at some distance in the rear, near the ground which was occupied by General Junot. Major General Crawford then sent to the officer who commanded in the village, which had been ceded in the morning, telling him that the possession of it was necessary to his corps, and therefore directing him to abandon it. The officer refused, with a declaration that he would die in defence of the post he was intrusted with. Major General Crawford immediately ordered six guns to open upon him, and some companies of the 43d and Rifle Corps to charge the village. The French were instantly driven out of it, and the advanced post of the light division put in possession of it.

The battle of Busaco was thus terminated. The French lost 10,000 men killed, wounded, and prisoners, in the course of the day; and Marshal Massena was first enabled to form an estimate of the talents of the General, and the bravery of the troops which he was directed to drive headlong into the sea.

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.