In the beginning of March, 1810, the second battalion was removed from Guarda to several pleasant villages in the valley of the Mondego, where the health of the men quickly improved. A numerous French army, under Marshal Massena, advanced and besieged Ciudad Rodrigo; and on the 1st of July the FIFTY-THIRD proceeded to the Coa river, to support the light division, observe the bridge of Castel Bom, and the ford of Juan Miguel. The enemy, having captured Ciudad Rodrigo, advanced in great force to invade Portugal; Lord Wellington, not having an army sufficiently numerous to oppose the French in the field, retired: the FIFTY-THIRD fell back from the Coa upon Guarda, and afterwards withdrew gradually before the enemy, until it arrived at the rugged rocks of _Busaco_, where the French legions found their advance impeded by a formidable line of British bayonets. The FIFTY-THIRD were detached a short distance to the left, to observe a small mountain road which came round that flank of the position, and during the action on the 27th of September their post was not attacked. The French, being unable to force the position, turned it by a flank movement; and the British retreated to the fortified lines of _Torres Vedras_, where they opposed a front of battle which the French did not venture to attack; but, after reconnoitring the lines fell back to Santarem, where they remained during the winter. [Sidenote: 1811] In Portugal the opposing armies confronted each other until the 5th of March, when the French, having lost many men, and being unable to procure provisions, made a sudden retreat towards the frontiers of Portugal. The FIFTY-THIRD followed the retreating enemy--several skirmishes occurred; and towards the end of March the battalion went into quarters at the hamlet of Romilioza, in the valley of the Mondego. Again advancing on the 2nd of April, the battalion approached the river Coa on the following day, when the French were driven from the vicinity of Sabugal. Four days afterwards it proceeded to Castel Bom; and on the 9th of April covered a reconnoissance, made by Colonel Fletcher of the Royal Engineers, on the fortress of _Almeida_, which was invested two days afterwards, when the FIFTY-THIRD took post on the east side of the town. They afterwards moved to San Pedro, and furnished piquets before the fortress. When Marshal Massena advanced to raise the blockade of Almeida, the FIFTY-THIRD quitted San Pedro and took their station in the position near _Fuentes d'Onor_. The attacks of the enemy on the 3rd of May were repulsed; on the 5th they were renewed, and the FIFTY-THIRD advanced to support the piquets, which were engaged among some stone fences to the left of the village. As it advanced, the battalion was exposed to the fire of a French battery, but did not sustain any loss: it took post at the foot of a hill, and supported the piquets until the action ceased: the French being repulsed, they afterwards retreated.