Complex sentence: They were split into the provinces Libya Superior and Libya Inferior in the Roman era and was part of Cyrenaica and the Pentapolis is also known as Western Pentapolis after the 5th century A.D. so as not to be confused with the other Pentapolises.
Split into simpler sentences: They were split into the provinces of Libya Superior and Libya Inferior in the Roman era and were part of Cyrenaica. The Pentapolis was also known as Western Pentapolis after the 5th century AD so as not to be confused with the other Pentapolises.