Complex sentence: Olivares, to counterbalance this situation, wanted to move the conflict into Catalonia, and so on July 19,1639, the French besieged and took the Fort de Salses in Roussillon.
Split into simpler sentences: Olivares, to counterbalance this situation, wanted to move the conflict into Catalonia. On July 19,1639, the French besieged and took the Fort de Salses in Roussillon.