Next to Sebastiani in the French line was a column composed of Girard’s division of the 5th Corps, the King’s Guards, and the Spanish regiments in Joseph’s service[131]. It was nearly 14,000 strong, and advanced straight up the Madrid _chaussée_, aiming at the Despeña-Perros and the Spanish centre. If the enemy should fight well, and if the flanking movements should fail, this column would have the hardest work before it: for, unlike the minor passes to east and west, the Despeña-Perros becomes in its central length a narrow and precipitous defile, easily capable of defence. The Spaniards had run entrenchments across it, and had mined the road at more than one point. But its fatal weakness lay in the fact that the by-paths from the western passes descend into it to the rear of the point where these obstructions had been placed. If they were seized by the advancing French, the fortifications across the _chaussée_ would prove a mere trap for the troops which held them. [131] Strength apparently: Girard, 7,040; Royal Guards, about 2,500; Spaniards, about 2,000; Cavalry, about 1,500; Artillery, &c., 800. Mortier, with Gazan’s division of the 5th Corps and Dessolles’ troops, about 15,000 strong, was told off to assail these flanking defiles on the Spanish left[132]. The two passes are the Puerto del Rey and the Puerto del Muradal. The former got its name from Alfonso VIII, who in 1212 had turned the position of the Almohad Sultan Mohammed-abu-Yakub by this route, and so forced him to the decisive battle of Navas de Tolosa, a few miles to the rear. In 1810 it was a tortuous and rough road, but practicable for artillery: the slopes on either side of it, moreover, were not inaccessible to infantry. A mile or two to its left, nearer the Despeña-Perros, was the still rougher path of the Puerto del Muradal, which was practicable for infantry but not for guns. Between this defile and the entrenchments across the Madrid _chaussée_, the crest of the Sierra was accessible to troops advancing in loose order and prepared for a stiff climb: the Spanish engineers had therefore placed a large earthwork on its culminating point, known as the Collado de Valdeazores. Giron’s weak division of no more than 3,200 bayonets was entrusted with the defence both of the Puerto del Rey and the Puerto del Muradal. Those of Lacy and Zayas, about 5,000 in all, held the Despeña-Perros and the entrenchments on each side of it. Areizaga lay behind them, with a reserve of 1,000 men at most--having sent off Castejon and his division to join Vigodet on the preceding night, he had no more with him than his personal guard, the ‘Batallón del General’, and some detached companies. [132] Gazan’s division, forming the third French column, had 6,414 bayonets; Dessolles’, the extreme right-hand column, 8,354.