The double nationality of João Rodrigues Cabrilho, Portuguese-born, naturalized Castilian. Part I – A much needed review
Authors: Afonso Paulo Manuel João 
Published: January 2023

This is a series of three papers revealing many important new connections between known historical documents and Alta California’s early maritime discovery. It brings new data about the complex network of individuals and events leading to this epic voyage, while focusing on the nationality of João Rodrigues Cabrilho and other Portuguese shipowners in Alvarado-Mendoça’s 1540-1543 fleet.
Remarkably, Part I presents Bartolome Ferrer’s unpublished 1547 testament, where Cabrilho’s pilot-major declares to be natural (likely as in being born, not naturalized) of Albissola, near Savona. Ferrer was Genoese, not Spanish, correcting what is currently accepted.
Furthermore, Part I critically reviews Cabrilho’s epoch international context, and gives many examples of naturalized foreigners who were not Spanish-born, seriously questioning the simplistic and premature conclusions about Cabrilho being Spanish-born based on W. Kramer’s 2015 important documental findings.
Part II details categoric evidence about Alvar Nunes, a Portuguese pilot, co-owner of the Santa María de Buena Esperança, very likely Cabrilho’s fleet second largest ship (perhaps rebaptized as Santa María de La Victoria). Noticeable, António Fernandes may have been the Portuguese owner of another ship in Alvarado’s fleet - the Anton Hernandez, alternatively indicated as Cabrilho’s fleet second largest ship.
Adding to Antonio de Herrera y Tordesillas’ sole confirmation (c. 1615) of Cabrilho’s Portuguese nationality, Part II details an extremely important 1604 map of California, done by the Florentine cartographer Matteo di Jacopo Neroni da Peccioli. Based on Spanish sources, this “novel” 1604 map (introduced in Part I) shows the toponym Cabrilho’s Bay, with the navigator’s name written in its Portuguese form (with lh), thus significantly reinforcing Cabrilho’s Portuguese nationality. Clearly, Herrera is not alone anymore.
Most crucially, supporting Cabrilho’s Portuguese nationality, new, diversified, and strong circumstantial evidence is documented regarding Juan Rodríguez(s) portugués (who was Cabrilho, in all verisimilitude) in Honduras and Nicaragua. While António Fernandes was a Portuguese neighbor of Granada (Nicaragua), Alvar Núñez portugués and Juan Rodríguez portugués (their names in Castilian written documents) met in León de Nicaragua, at least by October 1529.
Part II also presents Cabril’s parish (north of Portugal) ecclesiastic archive records of a Rodrigues family from the 1520’s. Furthermore, past centuries forgotten documents about nearby Mount Cabrilho, confirm that Cabrilho as a name did exist in Portugal.

Part II ends by discussing remarkable new Carbon-14 radioisotope chronological data strongly supporting early 1530’s as the time when Cabrilho offered a crucifix to his Rodrigues family in Lapela (de Cabril), in agreement with their ancestral oral tradition.

Part III addresses homonymous of Juan Rodríguez(s) portugués (like Panama’s rich Portuguese merchant) who were not Cabrilho, and homonymous of other key individuals in many of Cabrilho’s life events, including Francisco López portugués, perhaps also naturalized in nowadays Palma del Río. Finally, Part III also discusses what likely is the very first evidence about the existence of Cabrilho’s own testament.