By the day of the last assault (October 18) Wellington had clearly lingered too long, for very large reinforcements had just come up to join Souham, who on that morning was in a position to evict from before Burgos not only any mere ‘covering force’ that might be left opposite him, but the whole 35,000 men which formed the total of the allied host. For by now the Army of Portugal was recruited up to a strength of 38,000 men present with the colours: it had also just received the disposable battalions of the Bayonne Reserve, a strong brigade of 3,500 men under General Aussenac, and what was more important still--Caffarelli had appeared at Briviesca with the main field-force of the Army of the North. The operations of Home Popham, Mendizabal, Mina and Longa, which had detained and confused the French troops in Biscay and Navarre for the whole summer, had at last reached their limits of success, and having patched up affairs on the coast, and left some 20,000 men to hold the garrison places, and to curb the further raids of the British commodore and the Spanish bands, Caffarelli had come southwards with the whole of his cavalry--1,600 sabres,--three batteries, and nearly 10,000 infantry, forming the greater part of the divisions of Vandermaesen and Dumoustier. There were something like 50,000 French concentrated between Pancorbo and Briviesca on October 18th[68], while Wellington--allowing for his losses in the siege--had not more than 24,000 Anglo-Portuguese and 11,000 Spaniards in hand. The arrival of the Army of the North not only made the further continuance of the siege of Burgos impossible, but placed Wellington in a condition of great danger. It is clear that his campaign in the North had only been able to continue for so long as it did because Popham, Mina, and the Cantabrian bands had kept Caffarelli employed for a time that exceeded all reasonable expectation. It was really surprising that a small squadron and 10,000 half-organized troops, of whom a large part were undisciplined guerrillero bands, and the rest not much better, should have held the 37,000 men of the Army of the North in play for three months. But the combination of a mobile naval force, and of local levies who knew every goat-path of their native mountains, had proved efficacious in the extreme. It had taken Caffarelli the whole summer and much of the autumn to vindicate his position, and recover the more important strategical points in his wide domain. Even when he was marching on Burgos there was fierce fighting going on round Pampeluna, on which Mina had pressed in more closely when he heard of the departure of the general-in-chief. The Cantabrians and Navarrese did marvels for Wellington, and their work has never been properly acknowledged by British writers.