Kingdom of Castile in the context of "Castilian language"

Spanish (español) or Castilian (castellano) is a Romance language of the Indo-European language family that evolved from the Vulgar Latin spoken on the Iberian Peninsula of Europe. It originated in the Kingdom of Castile, a historical kingdom in north-central Spain. Today, it is a global language with 519 million native speakers, mainly in the Americas and Spain, and about 636 million speakers total, including second-language speakers. Spanish is the official language of 20 countries, as well as one of the six official languages of the United Nations. Spanish is the world's second-most spoken native language after Mandarin Chinese; the world's fourth-most spoken language overall after English, Mandarin Chinese, and Hindustani (Hindi-Urdu); and the world's most widely spoken Romance language. The country with the largest population of native speakers is Mexico.

Spanish is part of the Ibero-Romance language group, in which the language is also known as Castilian (castellano). The group evolved from several dialects of Vulgar Latin in Iberia after the collapse of the Western Roman Empire in the 5th century. The oldest Latin texts with traces of Spanish come from mid-northern Iberia in the 9th century, and the first systematic written use of the language happened in Toledo, a prominent city of the Kingdom of Castile, in the 13th century. Spanish colonialism in the early modern period spurred the introduction of the language to overseas locations, most notably to the Americas.

As of 1 October 2025, Spain had a total population of 49,442,844. The modern Kingdom of Spain arose from the accretion of several independent Iberian realms, including the Kingdoms of León, Castile, Navarre, the Crown of Aragon and Granada, all of which, together with the modern state of Portugal, were successor states to the late antique Christian Visigothic Kingdom after the Reconquista.

Spain's population surpassed 49 million inhabitants for the first time in history in 2025, with a total population of 49,442,844 people living in Spain. Its population density, at 97 inhabitants per square kilometre (250/sq mi), is much lower than other Western European countries, yet, with the exception of microstates, it has the highest real density population in Europe, based on density of inhabited areas. With the notable exception of Madrid, Spain's capital city, the most densely populated areas lie around the coast.

The Crown of Castile was a medieval polity in the Iberian Peninsula that formed in 1230 as a result of the third and definitive union of the crowns and, some decades later, the parliaments of the kingdoms of Castile and León upon the accession of the then Castilian king, Ferdinand III, to the vacant Leonese throne. It continued to exist as a separate entity after the personal union in 1469 of the crowns of Castile and Aragon with the marriage of the Catholic Monarchs up to the promulgation of the Nueva Planta decrees by Philip V in 1716.

In 1492, the voyage of Christopher Columbus and the discovery of the Americas were major events in the history of Castile. The West Indies, Islands and Mainland of the Ocean Sea were also a part of the Crown of Castile when transformed from lordships to kingdoms of the heirs of Castile in 1506, with the Treaty of Villafáfila, and upon the death of Ferdinand the Catholic. The discovery of the Pacific Ocean, the conquest of the Aztec Empire, the conquest of the Inca Empire, the Spanish conquest of New Granada as well as the conquest of the Philippines all helped shape the Crown of Castile into a global empire in the 16th Century.

The Iberian Crusades were papally promoted wars, part of the Reconquista, fought against the Muslim states of the Iberian Peninsula within the wider Crusading movement from 1095 to 1492. The Muslim conquest of the peninsula was completed in the early 8th century, when the Christian Visigothic Kingdom fell, yet the small realm of Asturias endured in the north-west. From the 9th century, its southward expansion against al-Andalus (Muslim Spain) was portrayed in local chronicles as a divinely sanctioned war of recovery. This expansion, along with Frankish advance, gave rise to new Christian realms—Navarre, León, Aragon, Castile, Portugal, and Barcelona—in the north. After al-Andalus split into taifas (small states) in 1031, the Christian realms exploited Muslim disunity to further expansion. From the 1060s, the papacy occasionally supported campaigns against al-Andalus by granting spiritual rewards to participants.

As the Reconquista advanced, the taifa rulers sought aid from the fundamentalist Almoravids of North Africa, who halted the Christian expansion. Soon after proclaiming the First Crusade for the liberation of the Holy Land at the Council of Clermont in 1095, Pope Urban II extended the same spiritual privilege—remission of sins—to Iberian lords who took up arms against the Moors (Iberian Muslims). Peter I of Aragon was the first ruler, in 1100, to fulfil his crusading vow within the peninsula, and his example was soon followed by others. Leading crusading armies, Alfonso I of Aragon captured Zaragoza (1118), Afonso I of Portugal seized Lisbon (1147), and Ramon Berenguer IV of Barcelona took Tortosa (1148). The renewed Christian advance provoked another North African intervention, this time by the Almohads, who could only temporarily halt the Christian expansion. Occasionally, the Moors' Christian allies, such as Alfonso IX of León were also targeted by crusading campaigns. After crusader forces inflicted a decisive defeat on the Almohads at the Battle of Las Navas de Tolosa in 1212, the Reconquista gained new momentum. Papal grants of crusade indulgence then supported James I of Aragon in the conquest of Mallorca (1231) and Valencia (1238), and Ferdinand III of Castile in the capture of Córdoba (1236) and Seville (1248), reducing al-Andalus to the Emirate of Granada by 1262.

The Cortes of León or Decreta of León from year 1188 was a parliamentary body in the medieval Kingdom of León. According to UNESCO, it is the first historically documented example of a parliamentary system.

After coming to power, King Alfonso IX, facing an attack by his neighbours, Castile and Portugal, decided to summon the curia regis or king's court/royal council to the Basilica of San Isidoro, León. This was a gathering of the nobility and the higher clergy called to advise the king, used in numerous countries during the Middle Ages. Because of the seriousness of the situation, Alfonso IX also called in representatives of the wealthy merchants and tradesmen from the most important cities of the kingdom, thus uniting the three Estates of the Realm in one council.

The Spanish language has two names: español (English: Spanish) and castellano (English: Castilian). Spanish speakers from different countries or backgrounds can show a preference for one term or the other, or use them indiscriminately, but political issues or common usage might lead speakers to prefer one term over the other. This article identifies the differences between those terms, the countries or backgrounds that show a preference for one or the other, and the implications the choice of words might have for a native Spanish speaker.

Today, the national language of Spain – the official Spanish language – is Spanish (as opposed to the regional languages of Spain, such as Galician, Catalan, Asturleonese, and Basque). Generally speaking, both terms (español and castellano) can be used to refer to the Spanish language as a whole, with a preference for one over the other that depends on the context or the speaker's origin. Castellano (as well as Castilian in English) has another, more restricted, meaning, relating either to the old Romance language spoken in the Kingdom of Castile in the Middle Ages, predecessor of the modern Spanish language, or to some formal varieties of Spanish which are popularly imagined as related to the historical region of Castile, in central Spain.

The history of Spain dates to contact between the pre-Roman peoples of the Mediterranean coast of the Iberian Peninsula with the Greeks and Phoenicians. During Classical Antiquity, the peninsula was the site of multiple successive colonizations of Greeks, Carthaginians, and Romans. Native peoples of the peninsula, such as the Tartessos, intermingled with the colonizers to create a uniquely Iberian culture. The Romans referred to the entire peninsula as Hispania, from which the name "Spain" originates. As was the rest of the Western Roman Empire, Spain was subject to numerous invasions of Germanic tribes during the 4th and 5th centuries AD, resulting in the end of Roman rule and the establishment of Germanic kingdoms, marking the beginning of the Middle Ages in Spain.

Germanic control lasted until the Umayyad conquest of Hispania began in 711. The region became known as Al-Andalus, and except for the small Kingdom of Asturias, the region remained under the control of Muslim-led states for much of the Early Middle Ages, a period known as the Islamic Golden Age. By the time of the High Middle Ages, Christians from the north gradually expanded their control over Iberia, a period known as the Reconquista. As they expanded southward, a number of Christian kingdoms were formed, including the Kingdom of Navarre, the Kingdom of León, the Kingdom of Castile, and the Kingdom of Aragon. They eventually consolidated into two roughly equivalent polities, the Crown of Castile and the Crown of Aragon. The early modern period is generally dated from the union of the Crowns of Castile and Aragon by royal marriage in 1469.

This is a list of kings regnant and queens regnant of the Kingdom and Crown of Castile. For their predecessors, see List of Castilian counts.