Octavian commissions the construction of a permanent palace for the emperor and his family in Rome. The palace, known today as the Palatium, lies to the left of the Forum Julium. Caesarion, now 16, joins the army, taking control of Legion 20 in Greece. Antony completely defeats the Armenian king, Tigranes, in the Battle of Athaxata. Afterwards, Antony beheads Tigranes and sends his head to Rome. Rome annexes the whole of Armenia. Agrippa and Antony campaign into northern Mesopotamia, taking several Parthian cities and engaging the Parthian satrap Zuphius at Praaspa. Agrippa and Antony barely win the battle due to casualties and are forced to retreat west to Gaugamela where they await the pursuing Zuphius. A revolt in Germania is defeated by Brutus and Marcus Corvinus.
Caesar and Scipio continue to capture cities in southern Persia, engaging several smaller Parthian armies and satraps during the year. In September, Phraates V engages Caesar at Tabae in the Second Battle of Tabae and Caesar captures the city. Phraates V then marches around Tabae and by November, Vordones and Phraates completely encircle Caesar’s army at Tabae. The Third Battle of Tabae ends in Caesar’s defeat and retreat to Susa, during which his army is constantly harassed by the Parthian army. Caesar’s retreat is immortalized by the 1483 painting by Leonardus of Vinci, Dedecus Roma (The Roman Shame). Scipio captures Rhagae by early November and turns his army south to engage Phraates and Vordones.