Historically, the Galician-Portuguese language originated in Galicia and Northern Portugal (comprising the Roman Gallaecia), and branched out since 14th century after the Portuguese expansion brought it southwards. There are linguists that consider Modern Galician and Modern Portuguese as dialects or varieties of the same language, but this is a matter of debate. For instance, in past editions of the Encyclopædia Britannica, Galician was termed a Portuguese dialect spoken in northwestern Spain, once often incorrectly considered a dialect of Spanish. However, the Galician government does not regard Galician as a variety of Portuguese, but rather as a separate language. After centuries of separation between the two languages, mutual comprehension can sometimes be difficult, although usually it is quite fluent.
Briefly, the relationship within the Galician-Portuguese sub-group can be compared with that between Moldovan and Romanian, Flemish and Dutch or Catalan and Occitan.
Galician is spoken by more than 3 million people, including most of the people in Galicia, as well as among the many Galician immigrants in the rest of Spain (Madrid, Barcelona, Biscay), elsewhere in Europe (Andorra, Geneva, London), and Iberoamerica (Buenos Aires, Montevideo, Havana).
Because of its historical status as a non-official language, for some authors, the situation of language domination in Galicia could be called "diglossia", with Galician in the lower part of the continuum, and Spanish at the top; while for others, the conditions for diglossia established by Ferguson are not met.
Spain has recognized Galician as one of Spain's four "official languages" (lenguas españolas), the others being Castilian (also called Spanish), Catalan (or Valencian), and Basque. Galician is taught at primary and secondary school and used at the universities in Galicia. Further, it has been accepted orally as Portuguese in the European Union Parliament and used as such by, among others, the Galician representatives José Posada, Camilo Nogueira and Xosé Manuel Beiras.