Trained as an industrial engineer, from a quite young age he dedicated himself to the study of the Catalan language. Through a group called L'Avenš, he promoted a campaign to reform Catalan orthography (1890-91), publishing in (1904) with Jaume Massˇ i Torrents and Joaquim Casas i Carbˇ a Tractat d'ortografia catalana. He participated actively in the First International Congress of the Catalan language (1906). In 1912 he published his Gramßtica de la llengua catalana.
Fabra moved from Bilbao to Barcelona in 1911, to become a professor (catedrÓtic) of Catalan -- a position created by the diputaciˇ (local government) of Barcelona -- and a member of the department of philology at the newly created Institut d'Estudis Catalans, of which he later became president.
In 1918, Fabra edited the textbook Curs mitjÓ de gramÓtica catalana, published by l'Associaciˇ Protectora de l'Ensenyanša Catalana (1918).
His "Converses filol˛giques", first published in the newspaper "La Publicitat", were later collected as "Popular Barcino". Probably his most famous work was the Diccionari general de la llengua catalana (1932), the first edition of what was later to become the Institute's official dictionary.
In 1932, owing to his scientific prestige, he was unanimously named a professor (catedrÓtic) of the Republican Universitat Aut˛noma de Barcelona (not to be confused with the later Universitat Aut˛noma de Barcelona created in the 60s during the Francoist rÚgime).
The Barcelona of this period, prior to the attempted destruction of Catalan culture and language by the forces of Generalísimo Francisco Franco was one in which intellectuals such as Fabra were well known and widely respected, and were Catalan was the everyday language in the street.
Imprisoned in 1934, he only became more popular in Catalonia. In 1939 he went into exile in France, where he was to live in Paris, Montpellier and Prada de Conflent. He presided over the literary competition of Jocs Florals in Montpellier in 1946. Every year, his tomb in CuixÓ near Prada, is visited by thousands of Catalans.
This article was translated from the Catalan-language wikipedia, which does not clarify the occasion of Fabra's 1934 arrest, but it was presumably immediately after the failed Catalan uprising of October 1934.