Soon after Foy’s arrival at Bilbao he was joined by Sarrut’s division of the Army of Portugal, which had followed him from Vittoria. He had therefore, counting Palombini’s Italians, the brigade of Aussenac, and the regular garrison of Bilbao, at least 16,000 men--ample for the task that Clausel had commended to him, the capture of Castro-Urdiales, with its patched-up mediaeval wall. The only thing presenting any difficulty was getting a siege train to this remote headland: Lameth, the Governor of Santoña, as it will be remembered, had been ordered to provide one, and there were four heavy guns in Bilbao:--the roads on both sides, however, were impracticable, and the artillery had to come by water, running the chance of falling in with British cruisers. On April 25th Foy marched out of Bilbao with his own, Sarrut’s, and Palombini’s divisions, more than 11,000 men,[395] leaving Aussenac on the Deba, to guard the road from San Sebastian, and Rouget in garrison as usual. On the same evening he reached the environs of Castro, and left Palombini there to shut in the place, while he went on himself to look for Mendizabal, who was known to be watching affairs from the hills, and to be blocking the road to Santoña, as he had so often done before. Foy then moved on to Cerdigo where he established his head-quarters for the siege, on a strong position between the sea and the river Agaera. Mendizabal was reputed to be holding the line of the Ason, ten miles farther on, but in weak force: he had only the _partidas_ of Campillo and Herrero with him, Longa being absent in the direction of Vittoria. On the 29th Foy drove off these bands at Ampuero, and communicated with Santoña, into which he introduced a drove of 500 oxen and other victuals. The governor Lameth was ordered to ship the siege train that he had collected to Islares, under the camp at Cerdigo, on the first day when he should find the bay clear--for three English sloops, the _Lyra_, _Royalist_, and _Sparrow_, under Captain Bloye, were lying off Castro and watching the coast. Foy then established Sarrut’s division to cover the siege at Trucios, and sent two Italian battalions to Portugalete to guard the road to Bilbao, keeping his own division and the three other Italian battalions for the actual trench work. The heavy guns were the difficulty--those expected from Bilbao were stopped at the mouth of the Nervion by the English squadron, which was watching for them--but in the absence of the sloops on this quest, the governor of Santoña succeeded in running his convoy across the bay on May 4th. The guns from Bilbao were afterwards brought up by land, with much toil.