Ney withdrew from the Ceira in the evening of the 16th, and on the 17th the light division forded that river with great difficulty, while the rest of the army passed over a trestle bridge, thrown in the night by the staff-corps. The French were, however, again in position immediately behind the Alva and on the Sierra de Moita, and they destroyed the Ponte Murcella and the bridge near Pombeira; while the second corps moved towards the upper part of the river, and Massena spread his foraging parties to a considerable distance, designing to halt for several days. Nevertheless the first, third, and fifth divisions were directed on the 18th, by the Sierra de St. Quiteria, to menace the French left, and they made way over the mountains with a wonderful perseverance and strength, while the sixth and light divisions cannonaded the enemy on the Lower Alva. As the upper course of the river, now threatened by lord Wellington’s right, was parallel to the line of Massena’s retreat, that marshal recalled the second corps, and, quitting the Lower Alva also, concentrated on the Sierra de Moita, lest the divisions, moving up the river, should cross, and fall on his troops while separated and in march. It then behoved the allies to concentrate also, lest the heads of their columns should be crushed by the enemy’s masses. The Alva was deep, wide, and rapid, yet the staff-corps succeeded in forming a most ingenious raft-bridge, and the light division immediately passed between Ponte Murcella and Pombeira; and at the same time the right wing of the army entered Arganil, while Trant and Wilson closed on the other side of the Mondego. Massena now recommenced his retreat with great rapidity, and being desirous to gain Celerico and the defiles leading upon Guarda betimes, he again destroyed baggage and ammunition, and abandoned even his more distant foraging parties, who were intercepted and taken, to the number of eight hundred, in returning to the Alva: for lord Wellington, seeing the success of his combinations, had immediately directed all his columns upon Moita, and the whole army was assembled there the 19th. The pursuit was renewed the 20th, through Penhancos, but only with the light division and the cavalry; the communication was, however, again opened with Wilson and Trant who had reached the bridge of Fornos, and with Silveira, who was about Trancoso. The third and sixth divisions followed in reserve, but the remainder of the army halted at Moita, until provisions, sent by sea from Lisbon to the Mondego, could come up to them. The French reached Celerico the 21st, with two corps and the cavalry, and immediately opened the communication with Almeida, by posting detachments of horse on the Pinhel, and at the same time Reynier, who had retired through Govea, occupied Guarda with the second corps.