From The Art and Popular Culture Encyclopedia
Spanish or Castilian (castellano) is a Romance language originally from the northern area of Spain. From there, its use gradually spread inside the Kingdom of Castile, where it evolved and eventually became the principal language of the government and trade. It was later taken to Africa, the Americas and Asia Pacific when they were brought under Spanish colonial rule between the 15th and 19th centuries.
Today, it is one of the official languages of Spain, most Latin American countries and Equatorial Guinea. In total, 21 nations use Spanish as their primary language. Spanish is also one of six official languages of the United Nations.
The language is spoken by between 322 and 400 million people natively.