with his whole army, the attempt was given up. Bourbon, Lannoy, and Pescara retired to Lodi; and the defence of Pavia was entrusted to Antonio de Leyva. Instead of following up the remnants of the imperial army to Lodi, and crushing them or driving them east into the arms of their uncertain Venetian allies, Francis turned aside to make himself master of Pavia. The siege artillery opened fire on November 6. An early assault having failed, Francis attempted to divert the course of the Ticino, and by this means to obtain access to the south side of the town, which relied mainly on the protection of the river. But the winter rains rendered the work impossible. Francis determined to reduce the city by blockade. Meanwhile he called up reinforcements from the Swiss, and took Giovanni de' Medici into his pay.
Italy prepared to take the side which appeared for the moment stronger. Venice hesitated in her alliance. Clement, while endeavouring to reassure the Emperor as to his fidelity, and ostensibly negotiating for an impossible peace, concluded, on December 12, 1524, a secret treaty with France, in which Florence and Venice were included. This treaty led both Clement and Francis to their ruin. Clement paid for his cowardly betrayal at the Sack of Rome, and Francis was encouraged to detach a part of his army under the Duke of Albany to invade Naples, an enterprise which weakened his main force without securing any corresponding advantage. The Duke, after holding to ransom the towns of Italy through which he passed, reached the south of the papal territory, where he was attacked by the Colonna and driven back to Rome. It was hoped however that this diversion would induce the imperial generals to leave Lombardy to its fate and hurry to the protection of Naples. But reinforcements were coming in from Germany under Frundsberg, and it was Naples that was left to fortune. On January 24, 1525, the imperial forces moved from Lodi. After a feint on Milan, they approached Pavia, and encamped towards the east to wait their opportunity. Thence they succeeded in introducing powder and other most necessary supplies into the famished city. The seizure of Chiavenna on behalf of Charles recalled the Grisons levies to the defence of their own territory. Reinforcements coming to Francis from the Alps were cut off and destroyed. Giovanni de' Medici was incapacitated by a wound. But the condition of the beleaguered city and lack of pay and provisions did not permit of further delay. It was decided to attack Francis in his camp and risk the issue.
On the night of February 24-25 the imperial army broke into the walled enclosure of the park of Mirabelle. Delays were caused by the solid walls and day broke before the actual encounter. The news of the attack induced Francis to leave his entrenchments and to muster his army, which consisted of 8000 Swiss, 5000 Germans, 7000 French infantry, and 6000 Italians. He was not much superior in actual
