In 1512 he concluded a treaty with King Ferdinand and the Venetian republic, which the allies called the 'Holy League.' The apparent object of this League was to defend the unity of the Church, and restore the ecclesiastical state; but the real object was directed against France.
Julius II.'s designs were helped by the Swiss, who entered Italy more than sixteen thousand strong, determined to re-establish Maximilian Sforza in the duchy of Milan; but the Pope and his allies received a check when a new general appeared at the head of the French army. Louis XII. had made his nephew, Gaston de Foix, Duke of Nemours, Governor of Lombardy. This young general of twenty-three soon distinguished himself by winning three victories in three months. By a well-planned march he brought help to the town of Milan, which was left without means of defence; and forced the Swiss to recross the mountains. He then obliged the Army of the League to raise the siege of Bologna. After reconquering Brescia, which was occupied by the Venetians, he marched on Ravenna, garrisoned by papal and Spanish soldiers. But his troops had hardly begun the attack when the Army of the League arrived with reinforcements. A battle took place on Easter Sunday, April 11th, 1512, outside the walls of Ravenna. Gaston de Foix, in the moment of victory, was surrounded, thrown from his horse and killed, as he was charging the retreating Spaniards. His death was disastrous to the French cause in Italy.
When Julius II. heard of Gaston's victories it is reported that he tore his beard with rage. One of Margaret's correspondents writes: 'Madame, there is news from Rome ... that after the Pope heard that the Venetians had taken Brescia, he expressed the greatest joy imaginable, and ordered the bells of Rome to be rung, fireworks, and many other rejoicings; but since he heard that his people and the Spaniards had retired from Bologna, he was much displeased, and caused a strong and furious letter to be written to the Viceroy of Naples, captain of the said Spaniards, ordering them to return to Bologna at once, and on no account to leave; and, moreover, when he heard that the French had retaken Brescia and slaughtered the Venetians, they say he tore his beard with rage.'
During this struggle the emperor remained passive. Although he agreed to Louis' proposed reforms, he evaded his promise to send German bishops to the Council the French king had convoked at Lyons. The truth was that Margaret had forbidden the bishops to attend. Louis naturally complained, and threatened the princess with his Government's displeasure. Margaret replied to his threats by reproaching him with his conduct in reference to the Duke of Gueldres. He protested that he had neither furnished the duke with men or money, but she would not accept his excuses, and soon after successfully formed a league between her father and the Kings of Spain and England, which league she said represented the mystery of the Holy Trinity.
Julius II. died on the 21st of February 1513. He had been one of the chief promoters of Italian independence, and through his warlike policy had considerably enlarged the papal states.
On the 11th of March 1513 Cardinal John de Medicis, then in his thirty-sixth year, was unanimously elected Pope by the twenty-four Cardinals assembled in conclave. The new Pope (Leo X.), who was of a peaceful and diplomatic nature, refused to ratify a treaty concluded at Malines on the 5th of April in the same year between Margaret, acting for her father, and Henry VIII.'s ambassadors; a treaty which would have forced him to send the papal troops to invade Provence or Dauphiny. He arranged a truce with Louis XII., who, after Gaston de Foix's death, had lost most of his Italian possessions. The Sforzas were reinstated in Milan, the Medicis in Florence, and Genoa became once more a free republic; the king's army was beaten by the Swiss at Novara, and by the English at Guinegate. A treaty signed at Blois, on the 28th of March, was ratified at Venice on the 11th of April. The Venetian republic agreed to help Louis to regain Milan and Genoa, and the king promised to assist the Venetians to recover their territories on the mainland, which were occupied by Maximilian's troops. The political balance of Europe now depended entirely on the goodwill of Henry VIII. On the 25th of May 1513 Jean le Veau wrote to Margaret that 'the time had come to be firm, and that she ought to imitate the English, who always showed their enmity against France.'
A treaty was concluded through Margaret's intervention in 1513 between the emperor and Henry VIII., which aimed at humbling France, but only resulted in the battle of Guinegate, where Maximilian served as a volunteer in the English army, and received a hundred crowns a day as pay. It was on this occasion that Margaret ordered the town of Therouenne on the borders of France and Belgium to be completely destroyed. Whilst he was with the English army Maximilian sent a messenger to Margaret asking her to join him at Tournay. In reply she says: 'Monseigneur, I have received the message that you have been pleased to send me by Marnix, my secretary, about my going to Tournay. As for me, Monseigneur, if you think that my going there is necessary, and can be of service to you, I am ready in this and in all else that it may please you to command me; but otherwise, it is not fitting for a widow to be trotting about and visiting armies for pleasure....' But a little later, after the reduction of Tournay, Margaret met her father and Henry VIII. at Lille.
In June of the same year King Ferdinand wrote to his ambassador in Flanders 'to tell Madame Margaret that before and after he concluded the truce with France in his own name as well as in the name of the emperor, the King of England, and Prince Charles, he wrote to his ambassador, Don Pedro de Urea, and ordered him to explain all his reasons to the emperor.... Having concluded the truce from pure necessity, he is forced to observe it this year.' King Ferdinand tells his ambassador to beg Madame Margaret to use her influence with the emperor, and to show him that the policy he has hitherto adopted can have only one result, viz. 'that of making the King of France master of the world; whilst if the emperor follows his (Ferdinand's) advice, nothing will be lost.'
He writes that 'Madame Margaret is willing to deliver Don Juan Manuel up to him as prisoner. She is to be told that Don Juan has not only behaved badly to King Ferdinand, but also speaks so ill of her that for this alone he deserves punishment.'[41]
And when, a little later, Margaret has asked Maximilian's permission to arrest Don Juan Manuel, because he had spoken against King Ferdinand, Maximilian answers that 'if Don Juan has committed a crime which is punishable according to law, he may be arrested; if not, it will be sufficient to banish him from the Court.'