Whilst these negotiations were under discussion, Henry VIII. was contemplating marrying his sister Mary to Louis XII., in order to prevent the French king's marriage with Eleanor of Austria. It was now in the King of England's interest to be on good terms with France, as he was deserted by those who had formerly sided with him against her. Full powers for Princess Mary's marriage with Louis XII. were sent to France on the 29th of July. The next day Mary solemnly renounced the promises made in her name with reference to her marriage with the Archduke Charles, and on the 7th of August the marriage contract with Louis was signed in London by the ambassadors, without Margaret having any suspicion of the truth.

When at last she heard rumours of the Anglo-French marriage, she did not believe them, and even ordered Jacques de Thienne, Lord of Castres, to tell the King of England that she had never believed the report to be true. De Castres only started on his mission in the middle of August, and the marriage treaty had been signed since the 7th of the same month, and Mary had married the prisoner Duke of Longueville[47] by proxy at Greenwich on the 13th.

This public ceremony at last convinced Margaret of the unwelcome fact that her nephew had been thrown over. She bitterly complained of King Henry's want of good faith, and threatened to publish the promise he had given in writing to marry his sister to the Archduke Charles.

Before Louis XII. married the eighteen-year-old Mary Tudor he sent his first painter, Jean de Paris, to London to paint her portrait and plan her trousseau. Accompanied by King Henry, Queen Katharine, and a great retinue of nobles as far as Dover, the bride set sail for France, escorted by the Duke of Suffolk. Amongst her ladies we find the names of the Ladies Grey and Anne Boleyn. Gorgeous pageants greeted Princess Mary; King Louis went himself in state to receive her at Calais, accompanied by the Duke of Valois and Margaret of Angoulême, and loaded her with presents and costly jewels. The wedding took place at Abbeville on the 9th of October. With reference to this marriage, Louise of Savoy, whose son, the Duke of Valois, was heir-presumptive to the throne, made the following spiteful entries in her diary: 'Le 22nd Septembre 1514, le roi Louis XII., fort antique et débile sortit de Paris, pour aller au devant de sa jeune femme, la reine Marie.'

'Le 9 Octobre 1514, furent les amoureuses noces de Louis XII., roi de France, et de Marie d'Angleterre; et furent épousés a dix heures du matin.'

On the 5th of November the new queen was crowned at St. Denis, and during the ceremony Francis, Duke of Valois, held the crown above her head.[48]

Henry VIII., in writing to thank Louis for a richly caparisoned Spanish genet which he had sent as a present, expressed his hopes that Mary's lively disposition might not harm conjugal peace. But Louis was quite fascinated by his youthful bride, and for her sake changed all his habits, and breakfasted at noon instead of eight in the morning, and went to bed at midnight instead of six, and soon ended by falling seriously ill. His wife amused him whilst he lay in bed by singing romances to her guitar; but three months after their marriage the worn-out old king of fifty-two died during a terrific storm which raged throughout New Year's night, 1515. Only a few faithful friends were with him at the last, and when next day Mary was informed of her loss she fainted, and with every sign of becoming grief shut herself up according to the custom of royal widows for six weeks in a darkened room.

Towards the month of March 1515 an English embassy was sent to France, headed by the Duke of Suffolk, to bring back the Queen-Dowager of France to England. Margaret writes to her father: 'Monseigneur, I have received your three letters of the 14th instant ... and in reply I write to inform you that the King of England has despatched a large embassy to the King of France, in charge of the Duke of Suffolk, who I hear is sent to bring back the Queen-Dowager.... As for the ambassadors who are to go to England with the Bishop of Brixen, I have communicated that part of your letters to the lord of Chièvres, as head of the finances and government of Monseigneur, who replied that the various personages were ready, but that the difficulty was finding money to provide them suitably. And I think, Monseigneur, he speaks the truth,' but, she adds sadly, 'I can do no more, for now I do not meddle in any business.'

After this date Margaret's letters to her father become much less frequent.

Soon after any dreams that she may have indulged in of a fourth and handsome husband in the person of Charles Brandon, Duke of Suffolk, were finally dissipated by his marriage with the young Queen-Dowager of France.[49] Mary Tudor was eighteen years younger than Margaret, and was considered one of the most beautiful princesses in Europe. These facts may account for Charles Brandon's preference. At any rate, after this episode Margaret remained a widow to the end of her life, and although the manuscripts in the British Museum abound with her letters to Henry VIII., Wolsey, and others on grave political affairs, they probably comprise no more than those already quoted that have so direct a reference to the affairs of her heart.[50]