The second season begins shortly after Caesar's murder. Octavian devises a plan to keep his family from fleeing the city, news that Antony happily delivers to a nervous Brutus. Meanwhile, Vorenus mourns Niobe's death but curses his children, and Pullo and Eirene get married without knowing what's happened back in Rome.
As gangs fight for control on the streets of Rome, Vorenus is called upon to undo some of the damage that he's done. Cleopatra pays a visit, bringing with her her son and Octavian becomes increasingly impatient with Mark Antony over the money he's owed.
Pullo tries in vain to persuade Vorenus to prevent a war among Aventine gangs; Antony's designs on Gaul elicit a shocking proclamation from Cicero to the Senate; Servilia enlists the opportunistic Duro to end an old feud; Brutus wrestles with his demons while seeking support in Bithynia.
Pullo races to find Vorenus with news of the fate of his children; Servilia pays a price for trying to eliminate a rival; a victorious Octavian sends word he's returning to Rome with his army, which comes as a surprise to Cicero; Timon grows weary of doing his mistress's bidding.
After his adventures with Antony and Pullo, Vorenus comes back to face the merchants of the Aventine Collegium; a pair of former foes reconcile their differences.
Vorenus is ordered to prune the ranks of Rome's elite; Brutus and Cassius prepare to face the recently allied Octavian and Antony in the Battle of Philippi; Levi and Timon create mayhem at a synagogue; Pullo thwarts Cicero's attempt to warn Brutus.
Octavian's campaign for a more virtuous society hits hardest in his inner circle; Vorenus's efforts to solve a gold robbery leave a bitter taste of betrayal; Pullo turns his grief about a personal loss into anger at a new enemy; Timon leaves Rome with his family for Jerusalem.
The people of Rome are starving. There have been many grain shortages over the past few months, but things have gotten particularly bad. In hopes of keeping the people from openly rebelling, Octavian sends Atia and Octavia to Alexandria in order to negotiate a deal with Mark Antony, though his real reasons for their trip is soon revealed. Meanwhile, Titus Pullo and Lucius Vorenus must try to keep the peace amongst many of the mercenaries who are in Rome.
After Marc Antony's defeat at Actium, he returns to Egypt, where he settles into a world of debauchery with Cleopatra. Octavian tries to use Pullo as leverage to Vorenus to gain access to the palace, but Vorenus stays loyal to Antony. Finally, it is Cleopatra who dupes Antony, saving her own life by sacrificing her honour. Ceasar Octavian triumphs in Rome.