To interrupt the communications of the French marshals, to whom he was about to oppose himself, was an object of paramount importance, and it was determined that an attempt should be made upon the pontoons and works at Almarez, it being the only passage practicable to an army, since the permanent bridges on the Tagus, from Arzobispo downwards, had been blown up. The French, aware of the value of this important passage, adopted every means within their power to protect it from being surprised, or assaulted with success. Both banks of the river were jealously fortified--the left of the Tagus being protected by a _tête-du-pont_[178] regularly intrenched and flanked, and commanded by Fort Napoleon--a strong redoubt placed on the high ground above the bridge. The fort was secured by an interior intrenchment, with a loopholed tower in the centre armed with nine pieces of cannon, and a garrison of four hundred men. Fort Ragusa, similar in strength and construction, commanded the right bank: it flanked the bridge with which it was connected by a _flêche_. At a league’s distance, a pass for carriages, called the Puerto de Miravete, winds through a steep sierra, and opens on an expanse of barren country entirely overrun with the gum-cistus.[179] There an old castle, standing on the crest of the heights, was fortified and surrounded by an enciente twelve feet high. The large venta on the road side was formed into a place of defence-- and with the two smaller works that connected it with the castle on the brow of the hill, altogether formed a line of very considerable strength. To destroy the bridge and works was a task intrusted to Sir Rowland Hill; and on the 12th of May, he moved from Almandralejo, with part of the second division and six 24-pound howitzers. He reached Jaraicejo early on the 16th, within eight miles of the summit of the pass--and there dividing his force into three columns, to each a separate duty was assigned. The left brigade under General Chowne, were directed to escalade the castle of Miravete, and for this purpose were provided with ropes and ladders. The centre, under General Long, with the howitzers, marched by the great road to attack the Puerto; while by a devious and rugged footway, Sir Rowland himself moved by Romangordo, to carry the bridge-works upon the right. The columns moved the same evening, but owing to the difficulties of the ground they could not reach their intended points of attack before daybreak. Sir Rowland, therefore, deferred the attempt until he should personally examine the works, and the troops bivouacked on the sierra. It proved that the castle, from its peculiar position, would require time to secure its reduction--and the least delay must prove fatal to success. General Chowne was therefore ordered to make a false attack with the left brigade, while the right, under General Howard, should steal down the broken side of the sierra, and attempt Fort Napoleon by a _coup de main_.