I believe that you have been slightly misinformed. Basically, in Spain (Hernandez) and Portugal (Hernandes), the names ending with an "ez" are of Visigothic (Germanic) origin, and they simply signify, originally, that you are the son of a Hernan or Hernando. Actually, Fernandez came first. This was taking place before the structure of surnames (or patronimics) as we know them today existed. People didn't really have two last names which would have indicated the last names of their father and mother. For example, we have that the prince (Infante in Spain) from Navarra, Fernan (or Fernando) Garciez de Hita, was the son of Garcia (that's why the Garciez), but the de Hita last name originated because he was also the descendant of Alvaro, Conde de Hita, who was an Asturian knight who first penetrated the walls of the Castillo de Hita when El Cid's relative and right-hand man, Alvar FaÃ±ez, took it from the Moors. Hita is located about 20 miles from Guadalajara, guarding the entrance into Guadalajara along the Valle del Henares from northern Spain. Now, the son of the Infante was Martin Fernandez (see, son of Fernando) de Hita. In this specific case only the first-born utilized the de Hita last name, which was considered an honor. although the half-brother of Martin Fernandez de Hita, named Pedro, also took the last name de Hita. This half brother of Martin, Pedro Fernandez de Hita was the founder and first master of the Order of Santiago.
I would also like to inform you that most Spanish (and others too) royal lines originating at the beginning of the Middle Ages probably had a Jewish origin, but the fact is that very few individuals know about the Kingdom of Septimania, which was a Jewish kingdom, and lasted about 150 years. The capital was Narbonne, in France, but the kingdom also included the cities of Barcelona and Pamplona (Navarra), on the southern side of the Pyrennes. The individuals who held the reigns of power in during those years, requested that individuals who descended from the line of David, establish a Jewish kingdom in the mentioned area. I would like to add that the town of Hita was one of the most active and wealthy Jewish communities in Spain, and we will find for example that one Manuel Levi, from Hita, was at one time the treasurer of the Kingdom of Castilla. It is also true that during the so-called Expulsion, several of the Jewish families of Hita, took it as a last name.
Oswaldo Hernandez Campos