The duke of Dantzic, apprised by the previous movements, that he was going to be attacked, became impatient; the state of the atmosphere prevented him from discovering the order of march, or the real force of the Spaniards; he knew that Blake had the power of uniting nearly fifty thousand men, and concluding that such a force was in his front, he resolved to anticipate his adversaries by a sudden and vigorous assault. In fact, the Spanish generals were so little guided by the rules of war, that before their incapacity was understood, their very errors being too gross for belief contributed to their safety. Blake had commenced a great offensive movement, intending to beat the troops in his front, and to cut off and capture Ney’s corps of sixteen thousand men. In six days, although unopposed, he advanced less than fifteen miles, and so disposed his forces, that out of thirty-six thousand men, he concentrated only seventeen thousand infantry, without artillery, upon the field of battle! [Sidenote: S. Journal of Operations, MS.] [Sidenote: Leith’s Correspondence. MS.] The duke of Dantzic, at the head of twenty-five thousand men, formed in three columns of attack, descended the heights of Durango. A thick fog covering the mountain sides, filled all the valleys; and a few random shots alone indicated the presence of the hostile armies. Suddenly Villatte’s division appeared close to the Spanish vanguard; and with a brisk onset forced it back upon the third division. Sebastiani’s and Leval’s followed in succession; a fire of artillery, to which Blake could make no reply, opened along the road: the day cleared, and the Spanish army, heaped in confused masses, was, notwithstanding the example of personal courage given by Blake, and the natural strength of the country, driven from one position to another. At mid-day it was beyond Zornosa, and at three o’clock in full flight for Bilbao, which place it gained in a state of great confusion during the night. The next day Blake crossed the Salcedon, and took a position at Nava. The duke of Dantzic pursued as far as Guenes, and then leaving general Villatte, with seven thousand men, to observe the enemy, returned to Bilboa. Twelve vessels, laden with English stores, were in the river, but contrived to escape. [Sidenote: S. Journal of Operations, MS.]