For the full realization of the meaning of the Lines of Torres Vedras there are two general facts which must be remembered. Firstly, they were garrisoned by troops which formed no part of the field army. Wellington’s sixty thousand regulars were not frittered away in the garrisoning of redoubts, but were held in masses behind the lines, ready to reinforce any threatened point, and to deliver a pitched battle in the open, if the head of the French army were thrust through the defences at some weak section. The generals of the seventeenth and eighteenth centuries, who so often built lines, and were so easily evicted from them, suffered disaster because they drew out their armies in one attenuated thread, and were therefore weak at every point, and always inferior to the assailant at the place where he made his assault. Wellington’s army was (with the exception of the 3rd Division at Torres Vedras) gathered in two solid masses, one facing Sobral, on the heights between Monte Agraça and Runa, the second and smaller behind Alhandra. The one could reach the other in half a day’s march, for the roads behind and parallel to the lines had been put in good repair.
The whole of this vast system of redoubts was to be held by the troops of the second line, and by them only. There were altogether some 20,000 men of the second line in the fortifications, composed of (1) the 8,000 (afterwards raised to 11,000) militia infantry. (2) Of about 800 Portuguese regular artillery, aided by over 2,000 gunners picked from the militia and Ordenança, trained by the regulars and incorporated with them. (3) Of some 250 British artillerymen from the batteries which had been lying in reserve at Lisbon. (4) Of picked companies of the Lisbon Ordenança (atiradores) drilled into a state of discipline not much worse than that of the militia. (5) Of the landing force of 2,000 British marines, partly from the fleet, partly brought specially from England to garrison the proposed lines of embarkation at St. Julian’s. (6) Of the dépôts, convalescents and recruits of the eight Line regiments of infantry raised from Lisbon and Southern Estremadura—about 4,000 strong.
In all, therefore, there were about 20,000 men, mostly troops of secondary quality, or 28,000 if the Spanish auxiliaries are counted, ready to man the Lines, without a man being withdrawn from the ranks of the field army. The outer lines were calculated to require about 18,000 men for the redoubts, the inner ones 14,000, but clearly both did not require to be manned at once. If the outer line were broken, the garrison-troops from the intact parts of it could fall back on the second. Meanwhile the field army would be engaging any French columns that might have broken through, and there would be ample time to arrange for the manning of the second and stronger front. But it must be repeated once more that it was not on the passive defence of the redoubts by their garrisons that Wellington reckoned for success, but on the fighting of the field army, who would tackle the columns of attack that had committed themselves to the assault of the section—whichever it might be—that Masséna might select as his objective. All criticism based on general principles concerning the weakness of long extended lines falls to the ground, when it is remembered that Wellington had his army massed for a pitched battle in and behind his defences, not strung out on an interminable front.
The last point on which stress must be laid is that the most careful arrangements for the transmission of orders and intelligence from end to end of the Lines had been made. There were five signal-stations, with semaphores worked by seamen on (1) the redoubt No. 30 near the Atlantic, (2) the great redoubt of Torres Vedras, (3) the Monte de Socorro above Wellington’s head quarters at Pero Negro, (4) the summit of the Monte Agraça, (5) the hill behind Alhandra on the Tagus. After some practice it was found that a message could be sent from one end to the other of the 29 miles in seven minutes, and from No. 3, the head quarters semaphore, to either end of the Lines in four minutes. There was a similar line of four semaphores on the second, or main, series of defences. Military roads had been opened behind both the fronts, so that troops could be moved along the shortest possible line. On the other hand, it was fortunate that there existed no cross-road from sea to sea outside the Lines, which could be of any practical use to the invader. The only route of this sort, that from Alemquer by Sobral to Runa, was commanded for the whole length from Sobral to Runa by the British heights, whose foot it hugs, while from Sobral to Alemquer it is separated from the Lines by the steep and pathless ridge of Galaria, across which nothing on wheels could pass. Nevertheless, here lay the invaders’ best chance—corps placed on this road, and screened by the ridge, could be moved for some distance to left or right unseen from the Lines. The road, however, was bad, rocky, and narrow: it is marked as the ‘Calçada Arruinada’ or ‘ruined road’ in contemporary maps. The other paved road in this direction, that from Sobral to Arruda and Alhandra, passed through the line of ground occupied by the British at two points, and was under fire from the redoubts at short range for the rest of its course: it was absolutely impracticable.
It only remains to be added that the navy had been utilized for auxiliary service: not only were its marines under orders to man the St. Julian’s lines, but its seamen had fitted out all the gunboats in the Lisbon arsenal. A flotilla of great strength infested the Tagus estuary, and by the fire of its heavy guns prevented the French from approaching the shore, or endeavouring to build boats at the mouths of its creeks. If any attacks had been made upon either of the extreme ends of the Lines, the columns delivering them would have been under fire from the sea throughout their operations. But, as we shall see, the French never contemplated this: the one temptation which Masséna felt was to assault, far inland, the gap in front of Sobral between the Monte Agraça and the Serra de Socorro. And there, as we shall see, at the critical moment, prudence got the better of ambition, and the invader turned back foiled. The high-water mark of French conquest in Europe was reached on the knoll by Sobral on the wet and gusty 14th of October, 1810.
SECTION XXI: CHAPTER V
MASSÉNA BEFORE THE LINES OF TORRES VEDRAS: HIS RETREAT TO SANTAREM (OCTOBER–NOVEMBER 1810)
On the night of October 10, when Craufurd made his hasty retreat to Sobral, and went within the Lines, Montbrun had his head quarters at Alemquer, where he kept Taupin’s infantry brigade, and Lamotte’s and Sainte-Croix’s cavalry. Pierre Soult’s light horse felt towards their left, in the direction of the Tagus, and occupied Carregado, where they failed to find any British outposts, Hill’s corps having been withdrawn behind the brook which enters the Tagus near Castanheira. The main body of the army was far to the rear, in one vast column: Ney’s and Reynier’s corps lay that night in and about Alcoentre: Junot’s bivouacked around the convent of Nossa Senhora de Maxeira, a short distance to the south of Alcoentre. All the troops were terribly fatigued by three days’ movement in torrential rain, and had no more marching-power left in them.
It was only on the following morning (October 11) that Montbrun discovered the Lines. His cavalry had been ordered to move forward on the two roads across which they lay. Pierre Soult therefore pushed for Villafranca, on the high road which skirts the Tagus; he found Hill’s outlying pickets at Villafranca, drove them out of the town, and on passing it came in sight of the line of redoubts and scarped hillside above Alhandra, which was manned by the Portuguese militia and backed by Hill’s British infantry. It was impossible to advance further, so the brigadier, leaving an advanced post in Villafranca, drew back his three regiments to Castanheira, and sent his report to Montbrun.