Francis having, by this transaction, deprived the Emperor of his two most powerful allies, and at the same time having secured a passage for his own troops through their territories, formed a scheme of attacking the kingdom of Naples, hoping either to overrun that country, which was left altogether without defence, or that at least such an unexpected invasion would oblige the viceroy to recall part of the imperial army out of the Milanese. For this purpose he ordered six thousand men to march under the command of John Stuart, Duke of Albany. But Pescara, foreseeing that the effect of this diversion would depend entirely upon the operations of the armies in the Milanese, persuaded Lannoy to disregard Albany's motions, and to bend his whole force against the King himself; so that Francis not only weakened his army very unseasonably by this great detachment, but incurred the reproach of engaging too rashly in chimerical and extravagant projects.
By this time the garrison of Pavia was reduced to extremity; their ammunition and provisions began to fail; the Germans, of whom it was chiefly composed, having received no pay for seven months, threatened to deliver the town into the enemy's hands, and could hardly be restrained from mutiny by all Leyva's address and authority. The imperial generals, who were no strangers to his situation, saw the necessity of marching without loss of time to his relief. This they had now in their power. Twelve thousand Germans, whom the zeal and activity of Bourbon taught to move with unusual rapidity, had entered Lombardy under his command, and rendered the imperial army nearly equal to that of the French, greatly diminished by the absence of the body under Albany, as well as by the fatigues of the siege and the rigor of the season.
But the more their troops increased in number, the more sensibly did the imperialists feel the distress arising from want of money. Far from having funds for paying a powerful army, they had scarcely what was sufficient for defraying the charges of conducting their artillery and of carrying their ammunition and provisions. The abilities of the generals, however, supplied every defect. By their own example, as well as by magnificent promises in name of the Emperor, they prevailed on the troops of all the different nations which composed their army to take the field without pay; they engaged to lead them directly toward the enemy, and flattered them with the certain prospect of victory, which would at once enrich them with such royal spoils as would be an ample reward for all their services. The soldiers, sensible that, by quitting the army, they would forfeit the great arrears due to them, and eager to get possession of the promised treasures, demanded a battle with all the impatience of adventurers who fight only for plunder.
The imperial generals, without suffering the ardor of their troops to cool, advanced immediately toward the French camp. On the first intelligence of their approach, Francis called a council of war to deliberate what course he ought to take. All his officers of greatest experience were unanimous in advising him to retire, and to decline a battle with an enemy who courted it from despair. The imperialists, they observed, would either be obliged in a few weeks to disband an army which they were unable to pay, and which they kept together only by the hope of plunder, or the soldiers, enraged at the nonperformance of the promises to which they had trusted, would rise in some furious mutiny, which would allow their generals to think of nothing but their own safety; that meanwhile he might encamp in some strong post, and, waiting in safety the arrival of fresh troops from France and Switzerland, might before the end of spring take possession of all the Milanese without danger or bloodshed. But in opposition to them, Bonnivet, whose destiny it was to give counsels fatal to France during the whole campaign, represented the ignominy that it would reflect on their sovereign if he should abandon a siege which he had prosecuted so long, or turn his back before an enemy to whom he was still superior in number, and insisted on the necessity of fighting the imperialists rather than relinquish an undertaking on the success of which the King's future fame depended. Unfortunately, Francis' notions of honor were delicate to an excess that bordered on what was romantic. Having often said that he would take Pavia or perish in the attempt, he thought himself bound not to depart from that resolution; and, rather than expose himself to the slightest imputation, he chose to forego all the advantages which were the certain consequences of a retreat, and determined to wait for the imperialists before the walls of Pavia.
The imperial generals found the French so strongly intrenched that, notwithstanding the powerful motives which urged them on, they hesitated long before they ventured to attack them; but at last the necessities of the besieged and the murmurs of their own soldiers obliged them to put everything to hazard. Never did armies engage with greater ardor or with a higher opinion of the importance of the battle which they were going to fight; never were troops more strongly animated with emulation, national antipathy, mutual resentment, and all the passions which inspire obstinate bravery. On the one hand, a gallant young monarch, seconded by a generous nobility and followed by subjects to whose natural impetuosity indignation at the opposition which they had encountered added new force, contended for victory and honor. On the other side, troops more completely disciplined, and conducted by generals of greater abilities, fought from necessity, with courage heightened by despair. The imperialists, however, were unable to resist the first efforts of the French valor, and their firmest battalions began to give way. But the fortune of the day was quickly changed. The Swiss in the service of France, unmindful of the reputation of their country for fidelity and martial glory, abandoned their post in a cowardly manner. Leyva, with his garrison, sallied out and attacked the rear of the French, during the heat of the action, with such fury as threw it into confusion; and Pescara, falling on their cavalry with the imperial horse, among whom he had prudently intermingled a considerable number of Spanish foot armed with the heavy muskets then in use, broke this formidable body by an unusual method of attack, against which they were wholly unprovided. The rout became universal; and resistance ceased in almost every part but where the King was in person, who fought now, not for fame or victory, but for safety. Though wounded in several places, and thrown from his horse, which was killed under him, Francis defended himself on foot with a heroic courage.
Many of his bravest officers, gathering round him, and endeavoring to save his life at the expense of their own, fell at his feet. Among these was Bonnivet, the author of this great calamity, who alone died unlamented. The King, exhausted with fatigue, and scarcely capable of further resistance, was left almost alone, exposed to the fury of some Spanish soldiers, strangers to his rank and enraged at his obstinacy. At that moment came up Pomperant, a French gentleman, who had entered together with Bourbon into the Emperor's service, and, placing himself by the side of the monarch against whom he had rebelled, assisted in protecting him from the violence of the soldiers, at the same time beseeching him to surrender to Bourbon, who was not far distant. Imminent as the danger was which now surrounded Francis, he rejected with indignation the thoughts of an action which would have afforded such matter of triumph to his traitorous subject, and calling for Lannoy, who happened likewise to be near at hand, gave up his sword to him; which he, kneeling to kiss the King's hand, received with profound respect; and taking his own sword from his side, presented it to him, saying that it did not become so great a monarch to remain disarmed in the presence of one of the Emperor's subjects.
Ten thousand men fell on this day, one of the most fatal France had ever seen. Among these were many noblemen of the highest distinction, who chose rather to perish than to turn their backs with dishonor. Not a few were taken prisoners, of whom the most illustrious was Henry d'Albret, the unfortunate King of Navarre. A small body of the rear-guard made its escape under the command of the Duke of Alençon; the feeble garrison of Milan, on the first news of the defeat, retired, without being pursued, by another road; and, in two weeks after the battle, not a Frenchman remained in Italy.
Lannoy, though he treated Francis with all the outward marks of honor due to his rank and character, guarded him with the utmost attention. He was solicitous, not only to prevent any possibility of his escaping, but afraid that his own troops might seize his person and detain it as the best security for the payment of their arrears. In order to provide against both these dangers, he conducted Francis, the day after the battle, to the strong castle of Pizzichitone, near Cremona, committing him to the custody of Don Ferdinand Alarcon, general of the Spanish infantry, an officer of great bravery and of strict honor, but remarkable for that severe and scrupulous vigilance which such a trust required.
Francis, who formed a judgment of the Emperor's dispositions by his own, was extremely desirous that Charles should be informed of his situation, fondly hoping that from his generosity or sympathy he should obtain speedy relief. The imperial generals were no less impatient to give their sovereign an early account of the decisive victory which they had gained, and to receive his instructions with regard to their future conduct. As the most certain and expeditious method of conveying intelligence to Spain at that season of the year was by land, Francis gave the commendador Pennalosa, who was charged with Lannoy's despatches, a passport to travel through France.
Charles received the account of this signal and unexpected success that had crowned his arms with a moderation which, if it had been real, would have done him more honor than the greatest victory. Without uttering one word expressive of exultation or of intemperate joy, he retired immediately into his chapel, and, having spent an hour in offering up his thanksgivings to heaven, returned to the presence-chamber, which by that time was filled with grandees and foreign ambassadors assembled in order to congratulate him. He accepted of their compliments with a modest deportment; he lamented the misfortune of the captive King, as a striking example of the sad reverse of fortune to which the most powerful monarchs are subject; he forbade any public rejoicings, as indecent in a war carried on among Christians, reserving them until he should obtain a victory equally illustrious over the infidels; and seemed to take pleasure, in the advantage which he had gained, only as it would prove the occasion of restoring peace to Christendom.