Beatrice of Aragon, daughter of Ferdinand I of Naples and Isabella of Clermont, was twice queen of Hungary by her marriages to Matthias Corvinus (in 1476) and, after his death in 1490, to Vladislaus II (in 1491), but the latter marriage was declared illegal by the pope in 1500, and she returned to Naples in 1502.
The Mellon chansonnier was most likely compiled as a wedding gift for Beatrice ca. 1475-1476.
San Francisco de Borja, IV duque of Gandía, was also a composer. Works attributed to him are: the 1551 liturgical drama Visitatio sepulchri, a Mass and a Ludi paschalis. The 16th-century inventory of Tarazona Cathedral choirbooks attributes to the Duke of Gandía the motet Exaltata in a lost manuscript; see Document 16/4 (1591)  in the following link: http://hispanicpolyphony.eu/node/16492
Juan de Borja y Castro was a nobleman and diplomat; he was the third son of San Francisco de Borja y Aragón, IV Duke of Gandía. He was the dedicatee of the manuscript B-Bc 27086, compiled in Vienna between 1577 and 1579, while Juan de Borja, I Count of Mayalde, served as mayordomo mayor of the Empress Dowager Maria of Austria, Philip II's sister and widow of Maximillian II. Juan de Borja was the oncle of the Duke of Lerma.
Alfonso de Vicente (2019), annotated: "Manuela de Bullón y Miñano era abulense, de la noble familia de los Bullones. Tomó el hábito el 6-VIII-1743, profesó el 9-VIII-1744 y murió al año siguiente, el 26-VIII"; he also mentioned a "Dúo con violines para la entrada de Dª Manuela Bullón en el convento de Santa Ana: Año de 1743, anónimo".