The assignment of educator and supervisor of the young prince is a sign of Arrazola's good reputation at Court, and of the great admiration and trust Eleonora and Cosimo have in him.
This becomes even more evident in the two "Libri Maestri di Eleonora" from 1554–58 and 1558–60, listing the Duchess's most faithful delegates trusted with managing monetary gifts and donations.
Contemporary chroniclers noted Fabio's special talent for remaining in the best graces of the young prince; one recounted that the Spaniard received "countless favors and gifts from him and his friends".
As such, in 1559 Arrazola receives the belongings of Alessandro Riccardi, those of Antonio de Nobili and Niccolò Alemanni, as well as a salary of 25scudi per month.
In this city palace Arrazola started housing his vast collection of Italian Renaissance art, as noted by Vasari in his famous Vite.
The King of Spain had written Francesco a letter asking to borrow 8,000 scudi, for which the Grand Duke would get the rights to Porto Ercole in return.
Fabio Arrazola can not be considered to have been a patron of the arts, yet he did own a considerable collection that he bought from the original commissioners or acquired through his patronage at the Santa Maria Novella.