How did people start to speak Spanish in Spain?

Spanish, a Romance language that originated in the Iberian Peninsula, became the dominant language of Spain through a combination of historical events and societal dynamics. Here's an overview of how it happened:

1. Pre-Roman Iberians: Before the arrival of the Romans, the Iberian Peninsula was inhabited by various indigenous tribes with their own languages.

2. Roman Conquest and Latin Influence: In the 2nd century BCE, the Romans conquered Hispania (present-day Spain) and introduced Latin as the lingua franca of administration, trade, and culture.

3. Vulgar Latin: Over time, the spoken Latin in Hispania evolved and diverged from Classical Latin, creating regional variations known as Vulgar Latin.

4. Germanic Invasions: In the 5th century, Germanic tribes, including the Visigoths, invaded Hispania and established kingdoms. They adopted and incorporated Latin into their own languages and social structures.

5. Reconquista and Linguistic Convergence: From the 8th to the 15th century, the Iberian Peninsula underwent the Reconquista, a period of wars between Christian kingdoms and Muslim-controlled territories. As Christian kingdoms expanded, Vulgar Latin and its evolving dialects spread, gradually leading to the formation of what we know as Spanish.

6. The Kingdom of Castile and Castilian Spanish: The Kingdom of Castile emerged as the dominant power during the Reconquista, and its dialect of Vulgar Latin, Castilian, became increasingly influential.

7. Cultural and Literary Developments: The 13th century marked a significant era for the development of Spanish literature and language. The Castilian language was used in influential literary works, such as "El Cantar de mio Cid," which helped standardize the language and consolidate its status.

8. Political Union and Expansion: The unification of Spain under the Catholic Monarchs, Isabella I of Castile and Ferdinand II of Aragon, in the late 15th century further solidified Castilian as the dominant language. As the Spanish Empire expanded, Spanish was taken to the Americas and other colonies.

9. Standardization and Royal Academies: In the 18th century, institutions like the Royal Spanish Academy (Real Academia Española) were established to standardize the Spanish language, codifying grammar, vocabulary, and spelling rules.

In summary, the development of Spanish in Spain was influenced by the Roman conquest and the imposition of Latin, subsequent Germanic influences, the Reconquista and the rise of the Kingdom of Castile, cultural and literary developments, and political unification. Over time, Castilian Spanish emerged as the dominant language of Spain and underwent standardization and codification.