The IEO is divided into regional and departmental sections and local circles that cover the whole of the country from the cities (called in vernacular language) of Lemòtges and Clarmont up north to Marselha, Tolosa or Bordèu down south.
The first Institute for Occitan Studies was created around 1923 as a section of the League of Meridional Homeland (Ligue de la Patrie Méridionale), but had a short lifespan.
In 1930, the Society for Occitan Studies (SEO) was founded by Joseph Anglade and Valère Bernard, with Louis Alibert as secretary.
The IEO went through several crises throughout its history, the most serious of which in the late 1970s and early 1980s when two ideologies clashed: the populist view of Ives Roqueta, and a more academic one promoted by Robèrt Lafont.
Most linguists among them migrated also to the Gidilòc and the Conselh de la Lenga Occitana ("Occitan Language Council").