Complex sentence: He is supposed to have been a Hellenized Roman, whose gentile name was possibly Valerius, living in the East, probably in Syria, where the fables seem first to have gained popularity.
Split into simpler sentences: He is supposed to have been a Hellenized Roman, whose original name may have been Valerius. He lived in the East, probably in Syria, where the fables seem first to have gained popularity.