Complex sentence: Lentas (Levin) is also known to be one of the two harbours of Gortys, which became the most prominent city of Crete after the fall of Knossos and the Province's capital during the Roman era, which also comprised Cyrnaica (ancient Libya).
Split into simpler sentences: Lentas (Levin) is also known to be one of the two harbours of Gortys, which became the most prominent city of Crete after the fall of Knossos. Gortys later was the Province's capital during the Roman era, which also comprised Cyrnaica (ancient Libya).