The emperor made great preparations on the side of Navarre; and though that frontier was well guarded by nature, it seemed now exposed to danger from the powerful invasion which threatened it. Charles besieged Fontarabia, which a few years before had fallen into Francis’s hands; and when he had drawn thither Lautrec, the French general, he of a sudden raised the siege, and sat down before Bayonne. Lautrec, aware of that stratagem, made a sudden march, and threw himself into Bayonne, which he defended with such vigor and courage, that the Spaniards were constrained to raise the siege. The emperor would have been totally unfortunate on this side, had he not turned back upon Fontarabia, and, contrary to the advice of all his generals, sitten down in the winter season before that city, well fortified and strongly garrisoned. The cowardice or misconduct of the governor saved him from the shame of a new disappointment. The place was surrendered in a few days; and the emperor, having finished this enterprise, put his troops into winter quarters. So obstinate was Francis in prosecuting his Italian expedition, that, notwithstanding these numerous invasions with which his kingdom was menaced on every side, he had determined to lead in person a powerful army to the conquest of Milan. The intelligence of Bourbon’s conspiracy and escape stopped him at Lyons; and fearing some insurrection in the kingdom from the intrigues of a man so powerful and so much beloved, he thought it prudent to remain in France and to send forward his army under the command of Admiral Bonnivet. The duchy of Milan had been purposely left in a condition somewhat defenceless, with a view of alluring Francis to attack it, and thereby facilitating the enterprises of Bourbon; and no sooner had Bonnivet passed the Tesin, than the army of the league, and even Prosper Colonna, who commanded it, a prudent general, were in the utmost confusion. It is agreed, that if Bonnivet had immediately advanced to Milan, that great city, on which the whole duchy depends, would have opened its gates without resistance: but as he wasted his time in frivolous enterprises, Colonna had opportunity to reënforce the garrison, and to put the place in a posture of defence. Bonnivet was now obliged to attempt reducing the city by blockade and famine; and he took possession of all the posts which commanded the passages to it. But the army of the league, meanwhile, was not inactive; and they so straitened and harassed the quarters of the French, that it seemed more likely the latter should themselves perish by famine, than reduce the city to that extremity.