Now the Swiss in the garrison at Navarra had been in communication with their compatriots in the vanguard of the ducal army, and when they found that they, who as a fact were unaware that Ludavico’s treasure was nearly exhausted, were better fed as well as better paid than themselves, they offered to give up the town and go over to the Milanese, if they could be certain of the same pay. Ludovico, as we may well suppose, closed with this bargain. The whole of Navarra was given up to him except the citadel, which was defended by Frenchmen: thus the enemy’s army was recruited by 3000 men. Then Ludovico made the mistake of stopping to besiege the castle instead of marching on to Mortara with the new reinforcement. The result of this was that Louis XII, to whom runners had been sent by Trivulce, understanding his perilous position, hastened the departure of the French gendarmerie who were already collected to cross into Italy, sent off the bailiff of Dijon to levy new Swiss forces, and ordered Cardinal Amboise, his prime minister, to cross the Alps and take up a position at Asti, to hurry on the work of collecting the troops. There the cardinal found a nest-egg of 3000 men. La Trimouille added 1500 lances and 6000 French infantry; finally, the bailiff of Dijon arrived with 10,000 Swiss; so that, counting the troops which Trivulce had at Mortara, Louis XII found himself master on the other side of the Alps of the first army any French king had ever led out to battle. Soon, by good marching, and before Ludovico knew the strength or even the existence of this army, it took up a position between Navarra and Milan, cutting off all communication between the duke and his capital. He was therefore compelled, in spite of his inferior numbers, to prepare for a pitched battle.