Alfonso was born in
Cáceres, region of
Extremadura, Spain. His family derived from
Galicia. Alfonso was educated in
Toledo. His father had putatively fought for Emperor Charles V in the
1541 expedition to Algiers, and died circa 1540 in a voyage of exploration of the American Pacific. In 1546, Alfonso moved to
Venice, where he found employment under
Diego Hurtado de Mendoza, the imperial ambassador to Venice. In that service, it is almost certain that Alfonso would have had contact with Mendoza's librarian,
Arnoldus Arlenius, who also worked at translating Ancient Greco-Roman classics. However, he was accused by an imperial captain and aides in the service of Mendoza of serving in Venice as a spy for the French. He fled Venice and served circa 1551 as a mercenary to
Ferrante I Gonzaga. However, by 1552 he was likely back in Venice mainly working on translations from Spanish to Italian. In 1552, the Gioliti firm published a translation by Ulloa into Spanish of
Girolamo Muzio's Il Duello (The Duel). For the same firm, he published translations into Italian of the texts of
La Celestina,
La cárcel de Amor by
Diego de San Pedro, poetry by
Garcilaso de la Vega, and
La Diana by
Jorge de Montemayor. Most of his works were eulogies of contemporary Imperial paladins and campaigns. In 1558, just months after the death of Charles V, he published a biography of the emperor. He initially worked mainly for the printing house of
Gabriele Giolito, but after 1556, he also worked with other firms. He was imprisoned in 1567 in Venice, putatively for falsifying an official permission from the
Council of Ten allowing him to publish a book in Hebrew. However, there is evidence that he was not protected, but may have been further impugned by the Spanish ambassador to Venice. Condemned to death, his sentence was commuted to life imprisonment. He died in jail in 1570. ==Works==