Spanish is a Romance language that originated in Spain and now has more native speakers worldwide than any language other than Mandarin Chinese. It is also called Castilian after the particular region of Spain, Castile, where it originated. According to Ethnologue, there are approximately 328.5 million people speaking Spanish as a native language and including second language speakers a total of 388 million speakers worldwide. Mexico contains the largest population of Spanish speakers. Spanish is one of the six official languages of the United Nations, and is used as an official language by the European Union and Mercosur.