On the morning of 24 February 1525, King Francis I of France charged across a foggy park outside Pavia at the head of his armoured cavalry, couched lances levelled at the Imperial relief force. His horsemen rode directly in front of his own cannons, blocking their fire. Behind him, his Swiss pikemen refused to fight. Within hours, the flower of French nobility lay dead or captured on the frozen ground of the Visconti Park.

Francis had laid siege to Pavia in October 1524 with over 26,000 troops—French foot soldiers, Swiss mercenaries, Germans, and Italian Black Bands—determined to regain the Duchy of Milan from the Holy Roman Emperor Charles V. The city held only 9,000 defenders under Antonio de Leyva, who melted church plate to pay them. By November, French artillery had breached the walls.

But Charles V sent a relief force of 22,300 men under the Flemish commander Charles de Lannoy and the French renegade Duke of Bourbon. Through December and January, the Imperial army pushed closer. Georg Frundsberg arrived with fresh German landsknechts. By February, Lannoy was within miles of Pavia, and Francis faced a choice: retreat or fight.

On the night of 23 February, Imperial engineers cut breaches in the park's walls. At dawn, arquebusiers poured through, followed by cavalry and pikemen spreading across the hunting reserve. The French did not grasp the scale of the assault until Spanish artillery opened fire. Francis, seeing the threat, launched his cavalry charge—the old medieval tactic, now obsolete against gunpowder.

His gendarmes scattered Lannoy's outnumbered cavalry in the first clash. But the charge had split his army and masked his own cannons. Frundsberg's landsknechts descended on the exposed French horsemen from all sides. Surrounded in the woods, unable to manoeuvre, the French cavalry was systematically killed. Francis's horse fell beneath him, shot by an Italian condottiero named Cesare Hercolani.

Surrounded by Spanish arquebusiers and German pikemen, Francis was taken prisoner. The battle was over by 9:00 am. His Swiss mercenaries tried to flee across the river and were slaughtered. His generals Bonnivet, La Palice, and Richard de la Pole lay dead. Over a thousand of his best soldiers perished in four hours of fog and confusion.

Francis was locked in the tower of Pizzighettone, then transferred to Madrid. Charles V forced him to sign the Treaty of Madrid, abandoning all claims to Milan and Burgundy. Francis denounced the treaty the moment he was released, but the damage was done: the age of French dominance in Italy was over, and the Holy Roman Emperor had proven the superiority of pike and shot over cavalry charge.