Niobe's fear of Vorenus is justified. Under Ancient Roman law, if a husband found out that his wife was unfaithful, he could legally kill her and her children.
Brutus appears to be in a dilemma when choosing sides, which is unsurprising. According to history, Brutus had no father, but Julius Caesar had acted as a foster father for most of his youth. Cato, however, was his uncle; the half-brother of his mother, Servilia.
The Roman soldiers in the camp that Pullo and his cavalry attack consist mostly of young adolescents, which is unsurprising. Ancient Roman law stipulated that a young man was an adult at 14, but many boys lied about their age and joined while they were much younger.
The storyline of the stolen gold was Bruno Heller's attempt to answer a question which has puzzled historians for centuries, which was why the gold wasn't removed when Pompey abandoned Rome.
The Latin writings on Atia's door read "Atia loves everyone", "Atia sucks (unreadable name)" and "Atia the lustful".