|Regions with significant populations|
|Castile and León||est. 1,500,000|
|Castilla-La Mancha||est. 1,000,000|
|Central & South America||Elsewhere est. 2,000,000|
|Related ethnic groups|
|Asturians, Leonese, Galicians, Basques, other Spanish peoples, Portuguese, French, Italian and other Europeans, Californios|
The Castilian people (Spanish: castellanos) are certain inhabitants in regions of central Spain including at least the eastern part of Castile and León, the northern and eastern parts of Castile-La Mancha, and the Madrid community, who are the source of the Spanish language (Castilian) among other aspects of cultural identity. However, not all people in the regions of the medieval Kingdom of Castile think of themselves as Castilian. For this reason, the exact limits of what Castile is today are disputed.
Through the Reconquista and other conquests in the Middle Ages, the Kingdom of Castile (later Crown of Castile) spread over a large part of the Iberian Peninsula, especially towards the southern Spanish regions. After this, since the 15th century, through the Spanish colonization of the Americas, the Castilians also spread over the New World, bringing with them not only their language, but also elements of their culture and traditions.
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 possible Basque influences. 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, Castilian is now usually referred to as Spanish.
Castilian (or Spanish) is the dominant language in Spain, and therefore was the language that was transmitted to the New World by the Conquistadores during the Spanish colonization of the Americas. Due to this gradual process, the Hispanophone world was created. As Castilian was the language of the Crown, it became the official language of all Spain, used side by side with other languages in their regions for centuries. During the years of the Franco dictatorship (1939 to 1975) there was an attempt to suppress the regional languages in favour of Castilian as the sole official language, causing a backlash against the use of Castilian in some regions after his death.
In Spanish, the word castellano (Castilian) is often used to refer to the Spanish language, alongside español (Spanish). See Names given to the Spanish language.
The overwhelming majority of native Castilians are Roman Catholic with various smaller foreign born populations of other Christian beliefs such as Protestants from eastern Europe or Latin America and Africans following Islam.