Siege of Milan (1523)

The Siege of Milan in 1523 was a military episode of the Italian War of 1521–1526 . The city's garrison, led by Prospero Colonna, managed to resist for almost two months a siege carried out by a numerically superior French army under the command of Grand Admiral Guillaume Gouffier de Bonnivet, who eventually abandoned the enterprise due to the impossibility of starving them out and the risk of being cut off from supplies himself.

In the summer of 1523, King Francis I of France launched a new military campaign aimed at reconquering the Duchy of Milan, which had been lost the previous year (except for a few castles and fortresses) following the defeat suffered at the Battle of Bicocca. The French managed to convince the Swiss Confederation to support them once again in the enterprise with an army of around 20,000 men and to block the mountain passes so that the Duchy would not be rescued by the Landsknechts, although the Canton of Zurich opposed this decision. In August, an army of around 18,000 men marched towards the Susa Valley but at the end of the month, when Francis I had already reached Embrun, he learned of the revolt of Charles III of Bourbon-Montpensier who had allied himself with Charles V and rebelled against his authority. He was thus forced to turn back with part of the troops and entrusted the command of the military campaign to Guillaume Gouffier de Bonnivet, Admiral of France.^[2]

In Milan in those same days, Duke Francesco II Sforza had just survived an assassination attempt by Bonifacio Visconti while he was riding on the road that connected the capital of the Duchy to Monza and had arrested some of the conspirators.^[3] Prospero Colonna, captain general of the imperial forces, was often confined to bed by a disease that caused him severe gastrointestinal symptoms and sometimes apoplectic fits. In any case, aware of the French king's moves, the Duke had sent messengers and money to Germany to recruit 6,000 lansquenets and had the supplies necessary to resist a long siege brought to Milan and Pavia.^[4]

On 5 September Colonna recovered and marched at the head of 6,000 infantry and 1,000 heavy Italian cavalry towards the banks of the Ticino, sending 2,000 Spanish infantry to garrison Novara and the same number to defend Alessandria. His aim was to delay, preventing the enemy from crossing the river until the arrival of the Landsknechts, 4,000 of whom were coming down from Val Camonica while the other 2,000 were camped around Trento.^[5] The French, led by Bonnivet, had in the meantime crossed the Alps, travelled through the Val di Susa and had camped between Turin and Asti with 12,000 infantry and 800 lances. The Swiss, after having assembled at Bellinzona, had reached Ivrea and were waiting for pay to join the French.^[6]

On 13 September the French, after having joined up with the Swiss in the Vercelli area, reached the western banks of the Ticino, planted artillery and began to fire on the enemy who had camped on the opposite bank near Boffalora, taking advantage of the favourable position due to the fact that the western bank was higher than the eastern one.^[7] The engineers in the meantime set about building two or three pontoon bridges to cross the river, which were completed that same evening. Colonna, perhaps taken by surprise by the speed of movement and by the intention of the French to head directly for Milan or Pavia and reluctant to risk a pitched battle, especially against an enemy with a significant numerical superiority, prudently decided to retreat from Boffalora and took up position at Bereguardo, awaiting the enemy's next move.^[8]

On September 15, Colonna sent Antonio de Leyva and Giovanni delle Bande Nere to garrison Pavia with 2,000 infantry and a few hundred cavalry each, and then decided to retreat to Milan. The French crossed the Ticino River unopposed, took Abbiategrasso, and that evening encamped at Binasco, halfway between Milan and Pavia.^[9] On 17 September the French sent 400 light cavalry to the park of the Porta Giovia Castle to inspect the city's defences, but Giovanni delle Bande Nere marched out with his light cavalry and forced them to retreat to Binasco. During the night Colonna called the people to arms to see if they were capable of rushing quickly to the defence of the city's fortifications, and the Milanese were ready. He then divided the 3,500 Spanish infantry and 4,000 lansquenets into three squads commanded by himself, the Duke, and Girolamo Morone, each of whom was assigned to defend one of the three gates of greatest strategic importance: Porta Vercellina, Porta Ticinese, and Porta Romana. The other gates and suburbs of the city were garrisoned by 2,500 Italian infantrymen who made up the mercenary companies in the pay of the Duchy of Milan, each thus found itself defended by 200-500 infantrymen. The reserve would have been made up of a citizen militia composed of 6,000 Milanese. The garrison of Milan remained awake all night but the French did not attack that day.^[10] On September 18, the French began clearing the southern side of the city and approached the Porta Ticinese hamlet. Fearing an assault, the Spanish infantry made a sortie which gave rise to a first skirmish in which the French lost 60 men and the Spanish 18 dead or wounded.^[11]

On 19 September the remaining 2,500 lanzichenecchi entered Milan. To prepare for the imminent siege, Colonna had the houses in the Porta Romana district that were outside the fortifications demolished and had them levelled. The French dedicated the day to diverting the course of the Naviglio Grande and the Martesana to prevent the water mills from working and to destroying those near Porta Vercellina, Porta Ticinese, Porta Comasina and along the Lambro. They also had the wagons and artillery cross the Ticino and camped between Gaggiano and San Cristoforo sul Naviglio, south-west of Milan. Shortly afterwards, de Leyva left Pavia, intercepted part of the wagons, massacred their guards and destroyed the southernmost of the three bridges built over the Ticino.^[12]

Two days later the garrisons of Tortona and Alessandria, about 2,000 infantry in all, entered Milan together with some papal reinforcements from Romagna. Along with these cities the French also occupied Monza, Novara and finally Lodi, previously garrisoned by the Marquis Federico II Gonzaga. On 24 September 10,000 French and 14 artillery pieces moved towards Cremona to besiege it. The remainder moved from San Cristoforo and Porta Ticinese and camped 5 miles south-west of Milan, near Chiaravalle. The village, famous for its Cistercian abbey (where Bonnivet lodged), would represent the French headquarters for the whole duration of the siege.^[13]

Meanwhile, the Milanese were faced with the impossibility of grinding wheat with watermills. They therefore brought a large number of millstones into the city so they could grind it by hand, began building several Apulian-style mills within the walls, and ordered the mountain villages to produce as much flour as possible, which would then be transported under escort to Milan on the roads that passed through Trezzo, Como, and the Brianza region. On October 1, in an attempt to cut off the supply route that passed through Trezzo, Bernabò Visconti moved from Cassano towards Trezzo at the head of 500 horsemen and attempted to assault the village, which, however, managed to resist thanks to its strong fortifications. He then decided to lay an ambush in the nearby woods while waiting for the next convoy. The next day, Giovanni delle Bande Nere left Milan and arrived in Trezzo to escort wagons containing flour. Having learned of the presence of French knights in the vicinity, he left a detachment of 500 arquebusiers in the woods between Trezzo and Vaprio d'Adda . When the French saw the convoy, they immediately attacked it, whereupon Giovanni lured them to the pre-arranged place by causing them to fall into an ambush in which most of them were captured or killed. Bernabò Visconti was wounded in the arm. That same evening Giovanni returned to Milan, parading wagons and prisoners amidst the jubilant cries of the people. The French, in retaliation, executed all the prisoners captured up to that point.^[14]

At the beginning of October, while bread was plentiful in Milan and was being sold at only slightly higher prices than usual, the French camp began to experience food shortages, partly due to insufficient supplies resulting from the constant raids by the Pavia garrison and Giovanni delle Bande Nere's light cavalry, and partly due to a shortage of sutlers who were unable to produce enough bread on site. Bonnivet then ordered his men to plunder the villages in the Milanese countryside and transport all the livestock to safety in Abbiategrasso. The hardship and delays in pay were, however, sufficient to push some of the Swiss to desert in small groups of 25-50 infantrymen, and the remainder to demand three wages not to return home and ten artillery pieces as hostages as a guarantee that the French would respect the agreement. Unable to do without them, the French had to give in to the demands. While on the one hand the French army was weakened by Swiss desertions, on the other hand it was strengthened by the arrival of thousands of infantry and some squads of knights led by Jacques de La Palice, Francis of Bourbon-Vendôme and Renzo degli Anguillara.^[15]

On 10 October, the Spaniard Hernando de Alarcón entered Milan and had a high bastion built near Porta Romana, placed some artillery pieces there and fired at the Swiss camp which suffered serious damage. The Swiss returned fire with their own cannons and managed to destroy the fortification. The next day the Spaniard had two more built and did the same for six hours in the direction of the French camp. A cannonball hit Bonnivet's nobleman who was standing next to him. On 12 October, the Spanish infantry, contravening orders, made a large sortie and clashed fiercely with the French; there were many dead and wounded on both sides but the Spanish managed to bring back 120 horses into the city, so that, after less than a month of siege, over 700 horses had already been captured from the French.^[16]

The French realized that given the city's size, fortifications, and large garrison, they would be unlikely to capture Milan by assault and that they would have to employ their forces to block all the city's supply routes, starving it to surrender. They therefore withdrew part of the troops sent to Cremona, sacked the Gera d'Adda, capturing Treviglio and Caravaggio, then stationed themselves in Cassano and from there began negotiations with the Brianza nobles to prevent the passage of supplies to Milan through their territory. Likewise, Milan knew that victory depended on a constant supply of food from the rest of the Duchy. On October 19, Colonna, strong enough to mount a horse, left the city and joined Federico II Gonzaga, preparing a plan to cut off the French supply routes crossing the Ticino River. The Marquis was supposed to lead his army ( 4,000 infantry, 500 light cavalry, 300 heavy cavalry) to Pavia where he would be joined by the 3,000 Spanish infantry and the 100 heavy cavalry of Vitello Vitelli who had just landed in Genoa . Together with them and part of the Pavia garrison he was then supposed to attack the French garrison near Boffalora and destroy the bridge, blocking the arrival of reinforcements and supplies from the west. At the same time Sforza gave his approval for the cession of Modena to Alfonso II d'Este in exchange for the support of the 3,000 cavalry of Guido Rangoni who were supposed to drive the French from Lodi or at least garrison Pizzighettone, blocking any possible supply to the French from the south-east.^[17]

During the night between October 24 and 25, the Spanish captured some French sentries posted just outside the walls, forced them under torture to reveal their names, and disguised themselves in their clothes. A group of them left the city and, having reached the French camp, managed to deceive the guards, enter, and surprise the enemy, killing 200-300 (with only 12 casualties) before they could reorganize for a counterattack. After this, they retreated within the walls. The five flags captured during the sortie were displayed in the cathedral. In retaliation, the French set fire to Rosate. After this assault, the French took steps to further fortify the camp, also considering making it suitable for wintering. New bastions were built and shelters were prepared, tents were largely replaced by wooden huts and shacks, trenches were extended almost to under the city walls and linked by covered roads to protect them from artillery fire, and soldiers stationed in the most advanced positions dug deep holes in the ground. The soldiers, however, had to deal with frequent autumn rains which at best turned the camp into a mudflat and forced them to sleep on straw mattresses or wooden planks, and at worst could flood it completely, making movement difficult and the artillery unusable.^[18]

Between 25 and 27 October 6,000 French infantry and 400 French lances occupied Monza, Vimercate and the castle of Carimate, sacking Cantù and the surrounding villages. At this point the nobles of Brianza were forced to collaborate so that their fiefdoms did not suffer the same fate, although many preferred to take refuge in Bergamo in Venetian territory. The initiative in fact significantly reduced the entry of provisions from the northern gates of Milan without however managing to starve the city. Milan in fact, although lacking wine and straw, had supplies of wheat, rice and fodder for two years, almost inexhaustible underground water reserves, a large quantity of livestock and chickens and was able to produce flour using as many as four hundred hand mills, not counting the windmills and some watermills still in operation near the Lazzaretto.^[19]

Unable to capture the city either by force or by starvation, the French attempted to take it by treachery. Giovanni Niccolò dei Lanzi and Morgante da Parma, two captains belonging to Giovanni delle Bande Nere's mercenary company, were contacted by Ludovico Barbiano da Belgioioso and Pietro Francesco Barbiano da Belgioioso, both loyal to the French cause, and the former was invited to meet them secretly in the French camp. He went there, and the three planned a conspiracy to gain control of the Porta Orientale. The plan was to be carried out during the night between October 28 and 29, when the guard of a ravelin of the gate would be entrusted to Morgante da Parma and his men. The conspirator was to post four sentries on the ravelin who, at a prearranged signal, would usher in some French infantry, waiting in the darkness a bowshot from the walls. Once inside, everyone would pin a white cross on their head and some would head to the gate where they would eliminate the guards, raise the gate and lower the drawbridge, allowing the French forces to enter.^[20]

Lanzi, however, confided the plan to a relative of his, an infantryman who served in Stefano Colonna 's company, who revealed it to his boss, and the latter to Sforza, who in turn informed Giovanni delle Bande Nere. Medici went to Porta Orientale and had Morgante da Parma arrested, while Lanzi managed to escape only to be captured by the Duke's guards. The two, along with three of the four sentries (one fled to the French camp), were taken to a house, their hands were tied behind their backs, and they were made to sit barefoot on the floor; their feet were then tied to planks and tortured with wax torches to reveal every detail of the conspiracy. The conspirators confessed, and it was discovered that Lanzi and Morgante had been promised a reward of 5,000 ducats and an annual pension of 500 ducats. Giovanni then went to Porta Orientale with his men and tried to lure the French into falling into a trap, but they, warned by the sentry who had escaped capture, did not show up under the walls. On the morning of the following day the conspirators were executed with pike blows by the Medici infantry and their bodies were then hung from some trees on the esplanade that looked towards the French camp. The Duke rewarded Lanzi's relative with 200 ducats, a pension of equal value, a house in Milan, Milanese citizenship and a place in his personal guard.^[20]

Between October 27 and 29, the forces of Federico II Gonzaga and Vitello Vitelli reached Pavia. On November 1, part of these troops left the city and managed to intercept a large convoy of wagons, killing around 100 infantrymen of the escort, capturing a hundred horses and seizing the supplies. On November 4, Pierre Terrail de Bayard and Renzo degli Anguillara left Monza and headed for Trezzo and Melegnano respectively. The French knight had in fact received letters in which the king ordered him to abandon the siege of Milan and retreat to France to quell the Montpensier rebellion. Anguillara, on the other hand, had to deal with the discontent of his men who intended to return home since the French were making no progress under the walls of Milan. Monza was soon occupied again by Milanese soldiers and supplies resumed from Como and Brianza. On 9 November the Venetian army led by the provveditore Leonardo Emo, which until then had remained in the Brescia area without providing aid to the Milanese as it should have done by agreement, moved on Treviglio forcing the French garrison to surrender, then camped at Canonica d'Adda and sent 1,000 arquebusiers to Milan under the command of Alessandro Donato.^[21]

On November 12, Galeazzo Sanseverino and Luigi di Brézé requested and obtained a meeting with Colonna, Morone, and Alarcón in a house in one of the hamlets of Milan. They proposed a six-month truce during which the lands east of the Ticino would remain in Sforza's possession while those to the west would be occupied by the French. Colonna stated that he did not have the authority to decide on the matter and that he would have to seek the opinion of the Viceroy of Naples, Charles of Lannoy . In any case, Sforza, once informed, rejected the proposal. On the evening of November 14, after having sent the wagons and artillery across the Ticino, the French lifted the siege and headed towards Abbiategrasso. There were many reasons that induced the French to abandon the enterprise in addition to the orders received from their sovereign. It was in fact now late autumn, the temperatures were rigid and it had already been snowing heavily for three days across the Po Valley, in the face of this there was a shortage of wood for heating. In the camp there was a shortage of food so much so that with a penny one could now buy barely 2 ounces of bread whereas in Milan for the same price sixteen ounces could be bought. All attempts to take Milan by starvation by cutting off the supply routes had failed. The French army finally risked being cut off from the Piedmontese strongholds by the garrison of Pavia.^[22]

In the following days, Sforza regained control of the Milanese countryside and part of the Gera d'Adda. Before retreating to the banks of the Ticino, the French entrusted the defence of Lodi to 2,000 infantry and 70 lances led by Ludovico Barbiano da Belgioioso and Giovanni Antonio della Somaglia.^[23]