Complex sentence: As the Spanish corps strength of 4000 to 5000 men approached the the area, the terrorized population pressed for surrender, but the firmness of Captain Brown prevailed who was at first expecting a long siege.
Split into simpler sentences: As the Spanish corps strength of 4000 to 5000 men approached the the area, the terrorized population pressed for surrender. The firmness of Captain Brown prevailed who was at first expecting a long siege.