The death of Alfonso I el Batallador (1134) without an heir was resolved in 1137 by the marriage of the daughter of King Ramiro I, Petronila, to Count Ramon Berenguer IV of Barcelona. The union of Catalonia and Aragon was a union of the dynasties agreed by a pact. Each of the kingdoms retained their lands, their laws, their institutions and their language. The descendants of Ramon Berenguer IV and Petronila took the title of kings of Aragon and counts of Barcelona. Alfons el Cast ruled Catalonia and Aragon, and also held the lands of Occitania in vassalage. The combined force of Catalonia and Aragon soon conquered Lleida and Tortosa.