'West Iberian' is a branch of the
Romance languages which includes
Spanish,
Ladino, the
Astur-Leonese group (
Asturian,
Leonese,
Extremaduran and
Mirandese), and the modern descendants of
Galician-Portuguese (
Galician,
Portuguese, and the
Fala language). According to
historical linguistic analysis, these languages are significantly closer to each other in historical terms than to any other living language in the peninsula — including
Catalan, the other major Romance language of the
Iberian Peninsula.

Languages of the Iberian peninsula (simplified)
Speakers of West Iberian languages generally claim that they are all
mutually intelligible to some extent. It is certainly true that a speaker of any of them can learn to read any other just by practicing, without formal study of the grammar. Bilingualism is quite common along the internal language boundaries of this group.
Until a few centuries ago, they formed a
dialect continuum covering the western, central and southern parts of the Iberian Peninsula — excepting the
Basque and Catalan speaking regions. This is still the situation in a few regions, particularly in the northern part of the Peninsula, but due to the differing sociopolitical histories of these languages (independence of
Portugal since the early 12th century, though briefly interrupted in the 16th and the 17th centuries; unification of
Spain in the 15th century under the
Catholic Kings, who privileged Spanish over the other Iberian languages), Spanish and Portuguese have tended to overtake and to a large extent absorb their sister languages, while they kept diverging from each other.
There is controversy over whether the members of the modern Galician-Portuguese and Astur-Leonese subgroups are
languages or
dialects. One classification, being much disputed, is to state that Portuguese and Galician are separate languages, while
Asturian,
Leonese,
Extremaduran and
Mirandese are dialects of an
Astur-Leonese language.
See also
★
Iberian Romance languages
★
Iberian languages