Usually, the dukes and counts of Gascony had two names, the first one being their given name, the second one being the given name of their father (for example, Duke Sans I Lop, which means this is Duke Sans I, son of Lop). This custom later generated the Spanish family names, with the adding of suffix -"ez" meaning "son of". "Juan Sánchez" literally means "John, son of Sancho". For a few dukes of Gascony, the second name is not the given name of their father, but it is a nickname that they gained over time and that replaced the given name of their father, such as the famous duke Sans III Mitarra, where "Mitarra" is not the name of his father, but a nickname referring to his origin, probably "Menditarra", with a typical Basque "-tarra" suffix to express origin.