Marshal Soult was, therefore, specially despatched from Germany to assume the chief command of the beaten army, and, if possible, restore its fallen fortunes.
Wellington foresaw the coming storm, and turned his immediate attention to the reduction of Pamplona and San Sebastian. From the strength of the former, and the excellent condition of its defences, the allied commander decided on a blockade; and it was accordingly closely invested by General Hill. Redoubts were thrown up within fifteen hundred yards of the place, armed with the cannon taken at Vitoria, and to the Spanish army under O’Donel the conduct of the blockade was entrusted.
Graham, with his corps augmented to ten thousand men, was directed to besiege San Sebastian; and on the 11th of July he sat down before the place.
San Sebastian is built on a peninsula, its western defences washed by the sea, and its eastern by the river Urumea, which at high water rises several feet above the base of the escarp wall. A bold and rocky height, called Monte Orgullo, rises at the extreme point of a narrow neck of land, and on its summit stands the citadel of La Mota.
Eight hundred yards distant from the land-front, the convent of San Bartolemeo, with a redoubt and circular fieldwork, were garrisoned. These advanced posts were strongly fortified, and, as it was determined to breach the eastern wall and storm it afterwards at low water, when the receding tide should permit an advance by the left of the Urumea, it became necessary, as a preliminary step, to dislodge the enemy from the convent.
On the 14th of July, the guns in battery opened a heavy fire on San Bartolemeo; and by the next day the walls of the building were injured considerably. Another battery, erected beyond the Urumea, fired with equal success upon the bastion; and on the 17th both works were carried by assault. Batteries, armed with thirty-two siege guns and howitzers, opened on the town wall from the sandhills; and on the 25th two breaches were effected, one of thirty yards extent, and the other of ten. A mine was also driven under the glacis, and at its explosion was the appointed signal for an assault upon the breaches.
At first the astounding noise distracted the garrison, and enabled the advance of both storming parties to gain the breaches; but the French recovered from their panic, and poured such a fire of grape and musketry on the assailants, that the breach was heaped with dead and dying, and the allies were driven back to the trenches with a loss of above six hundred men. The loss of the British, from the 7th to the 27th of July, amounted to two hundred and four killed, seven hundred and seventy-four wounded, and three hundred missing.
This severe repulse, added to the certain intelligence that Soult was preparing to strike a grand blow, induced Lord Wellington to issue immediate orders to raise the siege.
Circumstances, indeed, rendered that step unavoidable. The French were already in motion; Soult had forced the passes on the right, penetrated the valleys of the Pyrenees, and was marching to relieve Pamplona.
Lord Wellington had a most extensive, and, consequently, a very difficult position to defend, his corps d’armée covering an extent of country extending, from flank to flank, over sixty miles of mountains, without lateral communications, or the means of holding a disposable reserve in the rear of the passes, all of which must be defended, as the loss of one would render the defence of the others unavailing.