This position was too formidable, from its narrow front, to be easily assailed, and the enemy declined an attack. Soon after the French corps separated, and resumed their former cantonments. Marmont retired on the valley of the Tagus, Dorsenne fell back on Salamanca, Girard moved to Mafra, and Foy proceeded to Placentia. The French operations, on the whole, were a miserable failure. It is true, that Rodrigo was relieved--but in every other essay their designs had failed; and Wellington, with an inferior force, completely checked them. ARROYO DE MOLINOS, AND SIEGE OF TARIFA. Girard invades Estremadura.--Hill marches against him.--Surprises him at Arroyo de Molinos.--Spanish affairs.--Fall of Tarragona. Proceedings of the French.--Siege of Tarifa.--Total defeat of Laval. General Hill had established his head-quarters at Portalegre, and cantoned his division in the surrounding villages. The position was well chosen; and while it enabled him to observe Badajoz closely, he had the power of concentrating his troops at the shortest notice; while no movement of any consequence could be made by the enemy without the knowledge of the English general. After retiring from Ciudad Rodrigo, Soult had turned his attention against the newly-raised army of Castanos; and Girard, with a moveable column, was despatched into Estremadura, to narrow his line of action and cripple his supplies. Girard’s presence was most injurious, and threatened the very existence of an army whose means of sustenance must be drawn from the country alone. Throughout the Peninsular war, the Spanish commissariate was but a name. Castanos’ support, therefore, depended on his own exertions; and it was absolutely necessary that the French should be driven from that portion of Estremadura, or the Spanish general could not subsist his raw and ill-appointed levies. That task was consigned to Hill, assisted by some Spanish troops, under the command of Giron and Penne Villemur. Apprised of the advance of the allies, Girard fell back from Aliseda; and, after a cavalry affair with Villemur, he retired, first to Arroyo Puerco--and then, passing Caceres, marched on Tollemacha. Hill, on gaining correct intelligence of his route, proceeded by the shorter road of Aldea de Cano and Casa Antonio; while Girard, leaving a rear-guard at Albola, fell back on the morning of the 27th upon Arroyo de Molinos.