Complex sentence: Spain made several attempts to conquer and colonize the area, notably including Tristán de Luna's short-lived settlement in 1559, but it was not settled permanently until the 17th century, with the establishment of missions to the Apalachee.
Split into simpler sentences: Spain made several attempts to conquer and colonize the area, notably including Tristán de Luna's short-lived settlement in 1559. But it did not achieve permanent settlement until the 17th century, with the establishment of missions to the Apalachee.