Autonomous communities of Spain
Spanish legislation, most notably in the Statutes of Autonomy of the bilingual communities, use the term "own language", or "language proper to a community", to refer to a language other than Spanish that originated or had historical roots in that particular territory. The Statutes of Autonomy of the respective autonomous communities have declared Basque the language proper to the Basque Country and Navarre, Catalan the language proper to Catalonia, the Balearic Islands and the Valencian Community—where it is historically, traditionally and officially known as Valencian—and Galician to be the language proper to Galicia. There are other protected regional languages in other autonomous communities. As a percentage of total population in Spain, Basque is spoken by 2%, Catalan/Valencian by 17%, and Galician by 7% of all Spaniards. A 2016 Basque Government census revealed 700,000 fluent speakers in Spain (51,000 in Basque counties in France) and 1,185.000 total when passive speakers are included.
Castilians
Castilian ("castellano"), that is, Spanish, is the native language of the Castilians. Its origin is traditionally ascribed to an area south of the Cordillera Cantábrica, including the upper Ebro valley, in northern Spain, around the 8th and 9th centuries; however the first written standard was developed in the 13th century in the southern city of Toledo. It is descended from the Vulgar Latin of the Roman Empire, with Arabic influences, and perhaps Basque as well. During the Reconquista in the Middle Ages, it was brought to the south of Spain where it replaced the languages that were spoken in the former Moorish controlled zones, such as the local form of related Latin dialects now referred to as Mozarabic, and the Arabic that had been introduced by the Muslims. In this process Castilian absorbed many traits from these languages, some of which continue to be used today. Outside of Spain and a few Latin American countries, Castilian is now usually referred to as "Spanish".