Complex sentence: It was in 1929--when he christened these as "Marques de Ponent", "Western Marches"--that Catalan geographer Pau Vila used for the first time a term designating jointly the Aragonese comarcas where Catalan is spoken.
Split into simpler sentences: It was in 1929--when he christened these as "Marques de Ponent", "Western Marches"--Vila, Pau, Les marques de Ponent. Els homes, 1929, La Publicitat that Catalan geographer Pau Vila used for the first time a term designating jointly the Aragonese comarcas where Catalan is spoken.