The origin of the name Franco is Castilla in northern Spain. Franco means Free Man.
Although people were originally known only by their first names, it became necessary to adopt a second name to identify due to population growth.

The most common type of family name found in the region was the surname that derives from the name of the father. The most common surname in Spain is with the ending "ez".
Many Spanish name derived from Germanic names because of the Visigothic domination of the peninsula between the V and VIII century.