Francis I.'s veteran generals, Marshals La Tremoille and Chabannes, had advised him to pursue without pause the beaten and disorganized imperial army, which was in such plight that there was placarded on the statue of Pasquin at Rome, "Lost--an army--in the mountains of Genoa; if anybody knows what has become of it, let him come forward and say: he shall be well rewarded." If the King of France, it was said, drove back northward and forced into the Venetian dominions the remnants of this army, the Spaniards would not be able to hold their own in Milaness, and would have to retire within the kingdom of Naples.

But Admiral Bonnivet, "whose counsel the king made use of more than of any other," says Du Bellay, pressed Francis I.
to make himself master, before everything, of the principal strong places in Lombardy, especially of Pavia, the second city in the duchy of Milan.
Francis followed this counsel, and on the 26th of August, 1524, twenty days after setting out from Aix in Provence, he appeared with his army in front of Pavia.

On learning this resolution, Pescara joyously exclaimed, "We were vanquished; a little while and we shall be vanquishers." Pavia had for governor a Spanish veteran, Antony de Leyva, who had distinguished himself at the battle of Ravenna, in 1512, by his vigilance and indomitable tenacity: and he held out for nearly four months, first against assaults, and then against investment by the French army.
Francis I.and his generals occasionally proceeded during this siege to severities condemned by the laws and usages of war.

A small Spanish garrison had obstinately defended a tower situated at the entrance of a stone bridge which led from an island on the Ticino into Pavia.

Marshal de Montmorency at last carried the tower, and had all the defenders hanged "for having dared," he said, "to offer resistance to an army of the king's in such a pigeon-hole." Antony de Leyva had the bridge forthwith broken down, and De Montmorency was stopped on the borders of the Ticino.