Title: Arabic language influence on the Spanish language
Content:   The Spanish language, also called Castilian, is a Romance language that evolved from the dialects of Roman Vulgar Latin spoken in the Iberian peninsula. The first documents written in a language with some features specific of modern Spanish are ascribed to a number of documents from different monasteries in the area of Burgos and La Rioja in what is now northern Spain. However, Toledo in central Spain, which became the capital of the early Kingdom of Castile during its southward expansion, is where Spanish began to appear in a written form recognizable today. The pre-existing Mozarabic dialect of this region (i.e. the Romance present during Muslim rule) is therefore likely to have also had an influence on modern Spanish. 
Title: Official languages of Spain
Content:  Spanish is actually the native language of the majority of the population, although this is due in large part to the internal migration processes that occurred in Spain from the middle of the 20th century. The predominance of Spanish started in the Middle Ages with the Reconquista, expanding throughout the Kingdom of Castile (in which the language was born) and later to other areas in the Iberian peninsula; it had cultural prestige and was also spoken in part of the Kingdom of Aragon and of the Kingdom of Navarre. It gained importance in becoming an auxiliary language, along with commercial and diplomatic communication, in the 16th and 17th centuries. In the following centuries Spanish continued its expansion at the expense of the languages 
Title: Languages of Spain
Content:  León and Zamora. In terms of the number of speakers and dominance, the most prominent of the languages of Spain is Spanish (Castilian), spoken by about 99% of Spaniards as a first or second language. According to a 2019 Pew Research survey, the most commonly spoken languages at home other than Spanish were Catalan in 8% of households, Valencian 4%, Galician 3% and Basque in 1% of homes. Distribution of the regional co-official languages in Spain: Spanish is official throughout the country; the rest of these languages have legal and co-official status in their respective communities and (except Aranese) are widespread enough to have daily newspapers and significant book publishing 
Title: Spanish language
Content:   The Spanish language evolved from Vulgar Latin, which was brought to the Iberian Peninsula by the Romans during the Second Punic War, beginning in 210 BC. Previously, several pre-Roman languages (also called Paleohispanic languages)—some related to Latin via Indo-European, and some that are not related at all—were spoken in the Iberian Peninsula. These languages included Basque (still spoken today), Iberian, Celtiberian and Gallaecian. The first documents to show traces of what is today regarded as the precursor of modern Spanish are from the 9th century. Throughout the Middle Ages and into the modern era, the most important influences on the Spanish lexicon came from neighboring Romance 
Title: History of the Spanish language
Content:  The language known today as Spanish is derived from a dialect of spoken Latin, which was brought to the Iberian Peninsula by the Romans after their occupation of the peninsula that started in the late 3rd century BC. Influenced by the peninsular hegemony of Al-Andalus in the early middle ages, Hispano-Romance varieties borrowed substantial lexicon from Arabic. Upon the southward territorial expansion of the Kingdom of Castile, Hispano-Romance norms associated to this polity displaced both Arabic and the Mozarabic romance varieties in the conquered territories, even though the resulting speech also assimilated features from the latter in the process. The first standard norm of Spanish was brought forward in the 13th century by Alfonso X the Wise (who superseded Latin for 
Title: Names given to the Spanish language
Content:  Originally Castilian (castellano) referred to the language of the Kingdom of Castile, one of several northern kingdoms that spread across the Iberian Peninsula through the Middle Ages, from about the 8th to the 15th centuries. Traditionally the first recorded examples of written Castilian/Spanish are considered to be the Glosas Emilianenses, a number of isolated words added to a Latin text as an aid to the reader, dated to the eleventh century. Soon after that there begin to appear discursive texts in Castilian, such as the Cantar de Mio Cid. This early Romance language was derived from Latin and evolved into modern Spanish. However, the term Spanish (español) is a more recent term that first referred to Spain 
Title: History of Spain
Content:  into Castilian instead of Latin. At the same time, Catalan and Galician became the standard languages in their respective territories, developing important literary traditions and being the normal languages in which public and private documents were issued: Galician from the 13th to the 16th century in Galicia and nearby regions of Asturias and Leon, and Catalan from the 12th to the 18th century in Catalonia, the Balearic Islands and Valencia, where it was known as Valencian. Both languages were later substituted in its official status by Castilian Spanish, till the 20th century. In the 13th century many universities were founded in León and in Castile. Some, such as the Leonese Salamanca and the Castilian Palencia, were among the earliest universities in Europe. In 1492, under the Catholic Monarchs, the first edition of the Grammar of the Castilian Language by Antonio de Nebrija was published.
Title: Burgos
Content:  Spanish, also called Castilian, originated in Castile and spread throughout the Crown of Castile's possessions following the reconquista. It was eventually dispersed throughout the Spanish empire following the conquest and colonization of the Americas, and Spain after the union of the Catholic Monarchs's kingdoms being co-spoken with other languages. Of the many different variations and dialects found throughout the world, it's argued that the purest Spanish can be found in the region of Burgos due to the fact that the language first developed here in the 10th-century. The Spanish language can be traced back to the monastery of Valpuesta located 100 km north-east of the city of Burgos. The Valpuesta cartularies are significant in the history of the Spanish language, and their status as manuscripts containing the earliest words written in Spanish has been officially recognised. The first utterings of Spanish continued in the "Silos Glosses", recorded in the Burgos monastery of Santo Domingo de Silos.
Title: Languages of Spain
Content:  The languages of Spain (lenguas de España), or Spanish languages (lenguas españolas), are the languages spoken in Spain. Most languages spoken in Spain belong to the Romance language family, of which Spanish is the only language which has official status for the whole country. Various other languages have co-official or recognised status in specific territories, and a number of unofficial languages and dialects are spoken in certain localities.
Title: Official languages of Spain
Content:  Catalonia and of 42.9% of the residents in the Balearic region. Valencian (a variety of Catalan) is the native language of 35.2% of the population in that community and Basque is the native language of 33.7% of the Basque people and of 14.6% of those from Navarre. With the exception of Basque, which is a language isolate, all of the vernacular languages spoken now in Spain are Romance languages, within the family of the Indo-European languages. The majority belong to the sub-group of languages Iberian Romance, with the exception of Catalan/Valencian and Aranes, belonging to the Occitano-Romances and Aragonese. Affiliation between one subgroup or the other is a cause for active discussion.

Question: what was the first language spoken in spain?
Answer: Spanish Language.