This letter was accurate as to the numbers of the English army, but Napoleon was ignorant how strongly lord Wellington was thrusting Portugal forward in the press.
Massena had commenced the invasion before these instructions reached him; but to understand his operations it is essential to have a clear idea of the country in which they were conducted. The advanced positions of the allies extended from Almeida over the Sierra de Estrella, by Guarda to Fundao, Sarzedas, and Castello Branco: no enemy could penetrate that line unless by force, and a serious attack on any one point was to be the signal for a gradual retreat of the whole, in concentric directions towards the Lines. But, if Guarda were evacuated, the enemy while menacing Celerico, could move either by Belmonte or Covilhao and separate general Hill from lord Wellington, the distance between those generals being twice as great as the enemy’s perpendicular line of march would be.
To balance this disadvantage, the road from Covilhao was broken up, a Portuguese brigade placed in Fundao, and general Leith’s corps was stationed at Thomar, between two entrenched positions, which formed the second temporary line of resistance. The first of those positions was behind the Zezere, extending from the Barca de Codies to the confluence of that river with the Tagus. The second behind the Alva, a strong and swift stream descending from the Estrella and falling into the Mondego some miles above Coimbra. Both were strong, the rivers deep and difficult of access, and the Sierra de Murcella closely hugs the left bank of the Alva.
Hill’s line of retreat from Sarzedas to the Zezere, has been already noticed, and from that river to the Alva, there was a military road constructed through the mountains to Espinhal. But the country from Celerico to the Murcella, a distance of about sixty miles, is one long defile, lying between the Sierra Estrella and the Mondego. The ridge upon which Celerico stands, being a shoot from the Estrella, and encircled by a sweep of the Mondego, closes this defile in front. In like manner the Sierra Murcella, covered by the Alva river, closes it in the rear, and the intermediate parts are but a succession of smaller streams and lower ridges. The principal road was repaired and joined to the road of Espinhal, and a branch was also carried across the Mondego to Coimbra. Thus an internal communication was established for the junction of all the corps. Nevertheless, between Celerico and the Alva, the country was not permanently tenable, because, from Guarda and Covilhao, there were roads over the Estrella to Gouvea, Cea, and Gallices, towns in rear of Celerico; and the enemy could also turn the whole tract by moving through Trancoso and Viseu, and so down the right bank of the Mondego to Coimbra.
But lord Wellington keeping the head of his army one march behind Celerico, in observation of the routes over the Estrella, and his rear close to the Alva, was master of his retreat; and as the Mondego was fordable in summer and bridged at several points, he could pass it by a flank movement in a few hours. Now the right bank was also one great defile, lying between the river and the Sierra de Alcoba or Caramula. This mountain stretching with some breaks from the Douro to Coimbra, separates the valley of the Mondego from the coast line, and in approaching Coimbra sends out a lofty transverse shoot, called the Sierra de Busaco, exactly in a line with the Sierra de Murcella, and barring the way on the right bank of the Mondego in the same manner that the latter Sierra bars it on the left bank. Moreover this route to Coimbra was the worst in Portugal, and crossed by several deep tributaries of the Mondego, the most considerable of which were the Criz and Dao. The Vouga, however, opened a passage through the Alcoba near Viseu, and that way the French could gain the great road from Oporto, and so continue their movement upon Coimbra.
Such being the ground on both sides of the Mondego, the weakest point was obviously towards the Estrella, and lord Wellington kept the mass of his forces there. But Massena was ill-acquainted with the military features, and absolutely ignorant of the lines of Torres Vedras. Indeed, so circumspectly had those works been carried on, that only vague rumours of their existence reached the bulk of the English army; and many British officers imagined that the campaign was only to cloak the general’s intention of embarking when he reached Lisbon. In England the opposition asserted that he would do so: the Portuguese dreaded it; the French army universally believed it; and the British minsters seem to have entertained the same opinion; for at this time an officer of engineers arrived at Lisbon, whose instructions, received personally from lord Liverpool, were unknown to lord Wellington, and commenced thus:—“As it is probable that the army will embark in September.”
CHAPTER VI.
THIRD INVASION OF PORTUGAL.
Massena’s command, extended from the banks of the Tagus to the Bay of Biscay, from Almeida to Burgos, and the number of his troops present under arms exceeded one hundred and ten thousand men. From these must be deducted thirteen thousand in the Asturias and province of Santander, four thousand in the government of Valladolid, eight thousand under Serras at Zamora and Benevente, and lastly, the reserve of Bayonne under general Drouet, nineteen thousand strong, which, organized as a ninth corps had only entered Spain in August, being replaced at Bayonne by a fresh reserve under general Caffarelli. Thus, the active army of invasion did not much exceed seventy thousand; and as every man, combatant or non-combatant, is borne on the strength of a French army, not more than fifty-five thousand infantry and about eight thousand horsemen were with the eagles. The ninth corps had however orders to follow the traces of the prince of Esling, and the void thus left at Burgos and Valladolid was supplied by sixteen thousand of the young guard.