One of these was a niece of the king's, the daughter of the Comte de Foix; the other was Charlotte d'Albret, a daughter of Alain d'Albret, Duc de Guyenne, and sister to the King of Navarre.

Between these two Cesare was now given to choose by Louis, and his choice fell upon Charlotte.
She was seventeen years of age and said to be the most beautiful maid in France, and she had been reared at the honourable and pious Court of Jeanne de Valois, whence she had passed into that of Anne of Brittany, which latter, says Hilarion de Coste,( 1) was "a school of virtue, an academy of honour." 1 Eloges et vies des Reynes, Princesses, etc.
Negotiations for her hand were opened with Alain, who, it is said, was at first unwilling, but in the end won over to consent.

Navarre had need of the friendship of the King of France, that it might withstand the predatory humours of Castille; and so, for his son's sake, Alain could not long oppose the wishes of Louis.

Considering closely the pecuniary difficulties under which this Alain d'Albret was labouring and his notorious avarice, one is tempted to conclude that such difficulties as he may have made were dictated by his reduced circumstances, his impossibility, or unwillingness, to supply his daughter with a dowry fitting her rank, and an unworthy desire to drive in the matter the best bargain possible.

And this is abundantly confirmed by the obvious care and hard-headed cunning with which the Sieur d'Albret investigated Cesare's circumstances and sources of revenue to verify their values to be what was alleged.
Eventually he consented to endow her with 30,000 livres Tournois (90,000 francs) to be paid as follows: 6,000 livres on the celebration of the marriage, and the balance by annual instalments of 1,500 livres until cleared off.