The battle of Marignano or Melegnano (13-14 September 1515) was a French victory that restored their rule of the Duchy of Milan after a brief period of Swiss dominance, and that was probably the high point of Francis I's career in Italy (Francis I's First Invasion of Italy).
The French had first seized Milan in 1499, expelling Ludovico Sforza. He attempted to retake his duchy in 1500 but was defeated and captured, going into exile in France. The French then held Milan until 1512, when it fell to the Swiss, who installed Massimiliano Sforza as duke. The French attempted to retake Milan in 1513, but suffered a heavy defeat at Novara (6 June 1513) and were forced back across the Alps.
At the start of 1515 Francis I came to the French throne. One of his first aims was the regain control of Milan. He arranged an alliance with Venice, and with Henry VIII of England, although still faced a potentially powerful coalition of the Italian powers, including the Pope, the Emperor Maximilian, Ferdinand II of Spain, Florence, the Swiss and Milan.
Francis was unable to recruit Swiss troops, as they would be his first opponents in Italy. Instead he was able to recruit a number of German troops. He also had a contingent of troops from the Franco-Spanish border led by Pedro Navarra, a Spanish engineer who had changed sides after the Spanish refused to pay his ransom in the aftermath of the battle of Ravenna (11 April 1512). The army also included Charles IV, duke of Alencon, First Prince of the Blood and Francis's brother in law, Admiral Bonnivet, who would go on to suffer defeat in Italy in 1524. In all Francis probably invaded Italy with around 30,000 men.
The Swiss had been expecting a French invasion, and had rushed reinforcements into Milan. These troops were now guarding the more usual mountain passes, and so in August Navarra led the French over the Argentière Pass, a route that was rarely used by invading armies and that was unguarded. A second French force advanced along the Maritime Alps towards Genoa.
Soon after crossing the Alps the main French force defeated and captured a force of Italian cavalry under Prospero Colonna. Caught out by the unexpected appearance of the French, the Swiss retreated south-east from Ivrea to Vercelli, south-west of Novara. The French were able to advance towards Milan, but Swiss reinforcements were on their way.
By the start of September the Swiss had troops at Domo d'Ossola, Varese and Monza, north of Milan. The French entered into negotiations with the Swiss and on 9 September came to terms with part of the Swiss force. Around 10,000 Swiss troops are said to have left, leaving 15,000 to face the French.
On 9 September the French were at Binasco, just to the south of Milan. Their Venetian allies were some way to the south-east, near Cremona. The nearest Swiss allies at Piacenza, between the French and the Venetians, but Ramon de Cardona, commander of the Spanish force and Lorenzo de' Medici, the Papal commander didn't trust each other, and failed to block the Venetians.
On 10 September the Swiss moved to Milan, the French to Marignano or Melegnano, south-east of Milan, while the Venetians had slipped past the Spanish and Papal forces and weren't far to the east, at Lodi.
The French began work on a fortified camp spread out along the road from Marignano to Milan, from where Francis sent out a message asking the Venetians to join him.
The Swiss camp was divided into a peace camp and a war camp, with the war camp led by the Forest Cantons. Their leaders decided to trigger a battle that would unite the Swiss forces, and the morning of 13 September the Swiss army began to move towards the French.
The battle began in the middle of the afternoon of 13 September. The Swiss caught the French artillery by surprise, and managed to defeat the French vanguard and inflict heavy losses on the Landsknechts. They also defeated a Frecnh cavalry attack.
The Swiss then fought their way towards the main French body in its camp. They fought their way across the entrenchments, but were stopped by a counterattack led by Francis I, with Bayard fighting alongside him. This was followed by a five-hour fight at the edge of the French camp. This fighting ended at about 10pm by mutual consent the two sides prepared to renew the battle on 14 September.
The Swiss started the day with another heavy attack. This time the French artillery was able to fire properly, inflicting heavy casualties. The Swiss managed to reach the French lines, and another melee began. They also repulsed attacks by the French cavalry, and began to threaten the French rearguard. One Swiss contingent was sent even further to the rear in an attempt to destroy a bridge behind the French.
At about 8am Alviano arrived in the Swiss rear at the head of part of his cavalry. The Swiss sent a force to block his advance, but then at about mid-day began a skilful fighting retreat. Both sides had suffered very heavy losses during the fighting, and so the French pursuit wasn't conducted with any great vigour.
Losses for any battle of this period were always uncertain. At Marignano the Swiss probably lost around 6,000 dead, while the French lost 5,000. The main result of the battle was that the Swiss lost their enthusiasm for the war. Two days after the battle the unpaid Swiss troops began to retreat home. Massimiliano Sforza, the Swiss-supported Duke of Milan, surrendered the castles of Milan and Cremona, and went into a comfortable captivity in France.
The battle also triggered the collapse of the anti-French alliance that had been created at the start of the War of the Holy League in 1510. The Pope came to terms with Louis in December 1515 and made peace.
In March 1516 five Swiss cantons and the Emperor Maximilian launched another invasion of Milan, but this was easily defeated. In November 1516 the Swiss League made an everlasting peace with Francis, a rare example of a truly long-lived treaty that remained in place to the French Revolution. The war with Spain ended after Ferdinand II of Aragon died and was succeeded by the young Charles I (later the Emperor Charles V). He made peace with Francis at the Treaty of Noyon (13 August 1516), and with all of his allies gone Maximilian followed at the Treaty of Brussels of 4 December 1516.
Francis recognised the significance of the victory at the time. After the battle he was knighted by the famous French commander
Pierre Terrail, seigneur of Bayard.