Pompey Magnus had two sons that fought against Caesar: Cnaeus and Sextus. He never had a son named Quintus as is stated in the series.

Although they didn't have any scenes together, Kevin McKidd (Vorenus) and Tobias Menzies (Brutus) would discuss their characters and brainstorm about how to portray them, because they felt their characters went through very similar moral conflicts. Confirmed by Kevin McKidd on the season one DVD commentary.

Atia's character traits on the show were loosly based on those of Fulvia, Marc Antony's third wife. Servilia's role in the conspiracy to kill Caesar on the show was inspired by that of Brutus' wife Porcia. Confirmed on the DVDs.