Accordingly the main body of Del Palacio’s army, the regiments of Soria, Granada, and Borbon, with Wimpfen’s two Swiss battalions from Tarragona, marched on the Llobregat, drove in Lecchi’s outposts, and confined him to the immediate environs of Barcelona. The _somatenes_ came to give help in thousands, and a cordon of investment was established at a very short distance from the great city. On the seaside Lord Cochrane, with the _Impérieuse_ and _Cambrian_ frigates, kept up a strict blockade, so that Lecchi, with his insufficient and not too trustworthy garrison of 3,500 Swiss and Italian troops, was in a most uncomfortable position. If it had not been that Barcelona was completely commanded by the impregnable citadel of Monjuich, he could not have maintained his hold on the large and turbulent city. His last outpost was destroyed on July 31: this was the strong castle of Mongat, six miles out on the coast-road from Barcelona to Mataro. It was held by a company of Neapolitans, 150 men with seven guns. Attacked on the land-side by 800 _miqueletes_ under Francisco Barcelo, and from the sea by the broadside of the _Impérieuse_, the Italian officer in command surrendered to Lord Cochrane, in order to save his men from massacre by the Catalans. Cochrane then blew up the castle, and destroyed the narrow coast-road on each side of it by cuttings and explosions[316], so that there was no longer any practicable route for guns, horses, or wagons along the shore. Thus hemmed in, Lecchi began to send to Duhesme, by various secret channels, appeals for instant aid, and reports painting his situation in gloomy but not much exaggerated colours. He asserted that the _somatenes_ were pushing their incursions to within 600 yards of his advanced posts, and that there were now 30,000 Catalans in arms around him. If he had said 10,000 he would have been within the limits of fact. [316] For a good narrative of these operations see Lord Cochrane’s autobiography, i. 262-5. On August 6 the Captain-General, after carefully arranging his troops in the positions round Barcelona, sent off Caldagues to harass Duhesme in the north. This enterprising brigadier-general was given no more than four companies of regulars, three guns, and 2,000 _miqueletes_ from the Lerida district under their colonel, Juan Baget. Marching by the mountain road that goes by Hostalrich, and picking up many recruits on the way, he established himself on the fourteenth at Castella, in the hills that lie between Gerona and the sea. Here he was met by all the _somatenes_ of Northern Catalonia, under their daring leaders, Milans and Claros.