We do not know when the young Borgia was raised to this dignity, but it was some time after 1482.

The strong ties which existed between the cardinal and the Spanish court doubtless enabled him to have his son created Duke of Gandia in the kingdom of Valencia.

As Mariana remarks, he bought this dukedom for his son.
Don Pedro Luis, however, when still a young man, died in Spain, for a document of the year 1491 speaks of him as deceased, and mentions a legacy left by his will to his sister Lucretia.

The duchy of Gandia passed to Rodrigo's second son, Don Giovanni, who hastened to Valencia to take possession of it.
Meanwhile the fancy of the licentious cardinal had turned to other women.

In May, 1489, when Lucretia was nine years old, appears for the first time the most celebrated of his mistresses, Giulia Farnese, a young woman of extraordinary beauty, to whose charms the cardinal and future pope, who was growing old, yielded with all the ardor of a young man.
It was the adulterous love of this Giulia which first brought the Farnese house into the history of Rome, and subsequently into that of the world; for Rodrigo Borgia laid the foundation of the greatness of this family when he made Giulia's brother Alessandro a cardinal.