As the
Spanish colonization of the Americas progressed there were several
Guerrero lineages that made the trip across the ocean. It then comes to reason that in Old Spain, there were already many
Guerrero lineages.
There is no agreement as to what "type" of name
Guerrero was. Was it an "occupational" name such as
Miller,
Baker, or
Smith or was it an "attribute" name, such as Little, Strong, or Brown? Perhaps the answer is both, and therefore, from the very beginning the surname had several origins from several individuals.
What is certain was that it was borne by some knights, and therefore to some noble lineages. Among the orders of knights such as that of
Santiago, the Guerreros were involved. To qualify, a knight had to prove that he was of ancient Christian noble lineage on both his father's and mother's side. As for attestation, the earliest
Guerrero I've so far come across was a knight named Juan
Guerrero de
Soto, who was awarded membership to a
Spanish king's Order of the Band, in about 1333.
Most descriptions as to the specific origins of the name in Spain, that I've come across almost invariably mention virtually all regions of medievel Spain. It is not instrucive when "
Castile", "Leon", "
Aragon", and "Andalucia" are mentioned in the same paragraph especially without a chronological context, much less when one source contradicts another source. One gains the sense that it originated in all these places more or less simultaneously, at the worst, or that it had already spread far and wide before it was finally recorded, at best.
In terms of frequency and distribution of the name in modern Spain, maps on these sites can be instructive.
http://apellido.enfemenino.com/w/apellidos/apellido-guerrero...http://www.miparentela.com/mapas/detalles/guerrero.html