The Atlas Lingüístico de la Península Ibérica [Linguistic Atlas of the Iberian Peninsula] (ALPI) is known to specialists as the large domain Iberian Peninsula atlas, proposed in the first few years of the 20th century by Ramón Menéndez Pidal and his team at the philological section of the Center for Historic Studies (CEH) in Madrid, which was part of the Junta de Ampliación de Estudios (JAE). The project director for the ALPI was Tomás Navarro Tomás.
The Linguistic Atlas of the Iberian Peninsula (ALPI) emerged within the frame of the European Linguistic Geography of that time, at the beginning of the last century, fuelled by the publication of Jules Gilliéron’s Atlas Linguistique de la France (ALF). As Navarro Tomás’ explains in his Noticia Histórica del ALPI (1975: 9):

En 1914 quedaron ya definidas las líneas generales del proyectado atlas. En primer lugar, no se limitaría a la parte de España de lengua castellana, sino que abarcaría toda la unidad lingüística románica de la Península y se titularía Atlas Lingüístico de la Península Ibérica (ALPI). Su objeto sería recoger el material necesario para ofrecer una representación de la lengua popular hablada en pueblos menores y antiguos por personas iletradas o de escasa cultura, entre los cuarenta y los sesenta años de edad.
[ In 1914 the general guidelines for the projected atlas were established. First of all, the atlas would not be limited to the Castilian part of Spain, but would also encompass the whole Romance linguistic space of the peninsula, and would be known as the Linguistic Atlas of the Iberian Peninsula (ALPI). Its goal would be to collect the necessary material in order to offer a representative sample of the vernacular language as spoken in smaller and older towns, by illiterate people or those with little education, between forty and sixty years old. ]

Even though the project was planned at the beginning of the last century, it was delayed by circumstances and the ALPI questionnaires were not printed until 1930. Between 1931 and 1936 almost all the surveys were quickly completed. However, following the civil war, a long time would go by before, with the collaboration of several researchers from the original project and with the oversight of Navarro Tomás from exile, work was resumed at the CSIC that finally led in 1962 to the publication of the only volume that has appeared to date.
This page briefly summarizes the history of the atlas and its methodological background, and the progress of the CSIC’s intramural project, which since 2009 has been editing the unpublished ALPI materials, that will be searchable via the electronic tool found under the Search tab.