I read this series a while ago and I know I'm missing a lot of major characters here, so go ahead and add any I've left out.

Marius: ESTJ
Sulla: ?NT?
Julilla: ESFJ
Metrobius: ESFP
Lucius Decumius: ESTP
Aurelia: INTJ
Caesar: ENTJ
Cato: ?STJ
Pompey: ESFP
Cicero: ENFJ
Terentia: ESTJ
Servilia: ESFJ
Publius Clodius: E?F?
Fulvia: ENTP
Mark Antony: ESTP
Brutus: INFP
Porcia: ENFP
Octavian: INTJ
Livia: INTJ
Agrippa: ISTJ
Octavia: ISFJ
Cleopatra: ENTJ
Caesarion: ENFJ