Thus Bonet’s movement which only brought a reinforcement of six thousand infantry to Marmont, kept away Caffarelli’s reserves, which were twelve thousand of all arms, uncovered the whole of the great French line of communication, and caused the siege of Astorga to be commenced. And while Bonet was in march by Palencia and Valladolid to the position of Tordesillas, the king heard of Marmont’s retreat from the Tormes, and that an English column menaced Arevalo; wherefore not being ready to move with the army of the centre, and fearing for Avila, he withdrew the garrison from that place, and thus lost his direct line of correspondence with the army of Portugal, because Segovia was environed by the Partidas. In this state of affairs neither Wellington nor Marmont had reason to fight upon the Duero. The latter because his position was so strong he could safely wait for Bonet’s and Caffarelli’s troops, and meanwhile the king could operate against the allies’ communications. The former because he could not attack the French, except at great disadvantage; for the fords of the Duero were little known, and that of Pollos was very deep. To pass the river there, and form within gun-shot of the enemy’s left, without other combinations, promised nothing but defeat, and the staff officers, sent to examine the course of the river, reported that the advantage of ground was entirely on the enemy’s side, except at Castro Nuño, half-way between Pollos and Toro. While the enemy commanded the bridge at Tordesillas, no attempt to force the passage of the river could be safe, seeing that Marmont might fall on the allies’ front and rear if the operation was within his reach; and if beyond his reach, that is to say near Zamora, he could cut their communication with Ciudad Rodrigo and yet preserve his own with Caffarelli and with the king. Wellington therefore resolved to wait until the fords should become lower, or the combined operations of the Gallicians and Partidas, should oblige the enemy, either to detach men, or to dislodge altogether for want of provisions. In this view he urged Santocildes to press the siege of Astorga vigorously and to send every man he could spare down the Esla; and an intercepted letter gave hopes that Astorga would surrender on the 7th, yet this seems to have been a device to keep the Gallicians in that quarter for it was in no danger. Santocildes, expecting its fall, would not detach men, but the vicinity of D’Urban’s cavalry, which remained at Castromonte, so incommoded the French right, that Foy marched to drive them beyond the Esla. General Pakenham however crossed the ford of Pollos, with some of the third division, which quickly brought Foy back, and Marmont then endeavoured to augment the number and efficiency of his cavalry, by taking a thousand horses from the infantry officers and the sutlers.