Half the strategy of the campaigns of 1811-12-13 consisted in one of the combatants secretly collecting stores, concentrating his whole army, and then dashing at some important part of his adversary’s line, before the other could mass his forces in a corresponding way. If prompt, the assailant might gain a fortnight, in which he might either try to demolish the enemy in detail before he could concentrate, or else to take from him some important position or town. In 1811 Marmont and Dorsenne played this trick on Wellington, during the short campaign of El Bodon and Aldea da Ponte. They relieved Ciudad Rodrigo, and nearly caught some divisions of the English army before the rest could join. But missing the instant blow, and allowing Wellington time to draw in his outlying troops, they failed and went home. In 1812, on the other hand, the British general successfully played off this device on the French. He first concentrated in the north, and captured Ciudad Rodrigo in eleven days, before Marmont could mass his scattered divisions; then going hastily south he took Badajoz in exactly the same way, storming it after only nineteen days of siege. Soult drew his army together at the news of Wellington’s move, but had to bring troops from such distances, and to collect so much food, that he arrived within three marches of Badajoz only to hear that the place had just fallen. In dealing with the main geographical facts of the war it is fair to recollect that an invasion of Spain from France is one of the most difficult of undertakings, because the whole river and mountain system of the Peninsula lies _across_ the main line of advance from Bayonne to Cadiz, which the invader must adopt. While the French conquest must be pushed from north to south, both the streams and the Sierras of Spain all run at right angles to this direction, i.e. from east to west. In advancing from the Pyrenees to Madrid, and again from Madrid to Seville and Cadiz, the invader has to cross every main river--Ebro, Douro, Tagus, Guadiana, and Guadalquivir--and to force the passes of every main range. Moreover, as he advances southward, he has to keep his flanks safe against disturbance from the two mountainous regions, Catalonia and Portugal, which lie along the eastern and western coasts of the Peninsula. Unless the whole breadth of Spain, from the Atlantic to the Mediterranean, be occupied step by step as the invader moves on towards the Straits of Gibraltar, he can always be molested and have his lines of communication with France threatened. In the end it may be said that Napoleon’s whole scheme of conquest was shipwrecked upon the blunder of attacking Andalusia and Cadiz while Portugal was still unsubdued. Wellington’s constant sallies out of that country upon the French flank, in Leon and Estremadura, detained such large forces to protect the valleys of the Central Douro and Tagus that enough men were never found to finish the conquest of the south and east. And finally