Diocles is a character who was transported to Rome after the War of Actium and gained his freedom through the intercession of his friend and mentor, Tyrannio. This man had known Terenta, Cicero's wife, due to his tenure as a librarian cataloging Cicero’s extensive collection of books and manuscripts. Diocles' intellectual pursuits involve comparing and contrasting various historical transcripts, evident from his mention of discrepancies in texts from Andronicus of Rhodes and Apellicon of Teos.