…Francesco Sforza arrives the next morning with…
April 1522 CE
…Francesco Sforza arrives the next morning with sixty-four hundred additional troops, joining the cavalry near the bridge to the south of Colonna's camp.
Lautrec begins his attack at dawn on April 27.
The Black Bands brush aside the Spanish pickets, clearing the ground before the Imperial positions.
The French advance is headed by two columns of Swiss, each comprising about four thousand to seven thousand men, accompanied by some artillery; this party is to assault the entrenched front of the Imperial camp directly.
Lescun, meanwhile, leads a body of cavalry south along the Milan road, intending to flank the camp and strike at the bridge to the rear.
The remainder of the French army, including the French infantry, the bulk of the heavy cavalry, and the remnants of the Swiss, form up in a broad line some distance behind the two Swiss columns; behind this is a third line, composed of the Venetian forces under Francesco Maria della Rovere, the Duke of Urbino.
The overall command of the Swiss assault is given to Anne de Montmorency.
As the Swiss columns advance towards the park, he orders them to pause and wait for the French artillery to bombard the Imperial defenses, but the Swiss refuse to obey.
Perhaps the Swiss captains doubted that the artillery would have any effect on the earthworks; in any case, the Swiss move rapidly towards Colonna's position, leaving the artillery behind.
There is apparently some rivalry between the two columns, as one, commanded by Arnold Winkelried of Unterwalden, is composed of men from the rural cantons, while the other, under Albert von Stein, consists of the contingents from Bern and the urban cantons.
The advancing Swiss quickly come into range of the Imperial artillery.
Unable to take cover on the level fields, they begin to take substantial casualties; as many as a thousand Swiss may have been killed by the time the columns reached the Imperial lines.
The Swiss come to a sudden halt as the columns reaches the sunken road in front of the park; the depth of the road and the height of the rampart behind it—together higher than the length of the Swiss pikes—effectively blocks their advance.
Moving down into the road, the Swiss suffer massive casualties from the fire of d'Avalos's arquebusiers.
Nevertheless, the Swiss make a series of desperate attempts to breach the Imperial line.
Some parties manage to reach the top of the rampart, only to be met by the landsknechts, who have come up from behind the arquebusiers.
One of the Swiss captains is apparently killed by Frundsberg in single combat; and the Swiss, unable to form up atop the earthworks, are pushed back down into the sunken road.
After attempting to move forward for about half an hour, the remnants of the Swiss columns retreat back towards the main French line.
In the fields which they had crossed and before the rampart, they leave more than three thousand dead; among these are twenty-two captains, including both Winkelried and Albert von Stein.
Of the French nobles who had accompanied the Swiss assault, only Montmorency survives.
Lescun, with about four hundred heavy cavalry under his command, has meanwhile reached the bridge south of the park and fought his way across it and into the Imperial camp beyond.
Colonna responds by detaching some cavalry under Antonio de Leyva to halt the French advance, while Francesco Sforza comes up the road towards the bridge, aiming to surround Lescun.
Pontdormy holds off the Milanese, allowing Lescun to extricate himself from the camp; the French cavalry now retraces its path and rejoins the main body of the army.
Despite the urging of d'Avalos and several other Imperial commanders, Colonna refuses to order a general attack on the French, pointing out that much of Lautrec's army—including the bulk of his cavalry—is still intact.
Colonna suggests that the French are already beaten, and will soon withdraw; this assessment is shared by Frundsberg.
Nevertheless, some small groups of Spanish arquebusiers and light cavalry attempt to pursue the withdrawing Swiss, only to be beaten back by the Black Bands, which are covering the removal of the French artillery from the field.