brothers. One of them, Monaeses, fled to Antony and persuaded him to invade Parthia. Antony defeated Parthia's Judaean ally Antigonus in 37 BC, installing Herod as a client king in his place. The following year, when Antony marched to Theodosiopolis, Artavasdes II of Armenia once again switched alliances by sending Antony additional troops. Antony invaded Media Atropatene (modern Iranian Azerbaijan), then ruled by Parthia's ally Artavasdes I of Media Atropatene, with the intention of seizing the capital Praaspa, the location of which is now unknown. However, Phraates IV ambushed Antony's rear detachment, destroying a giant battering ram meant for the siege of Praaspa; after this, Artavasdes II abandoned Antony's forces. The Parthians pursued and harassed Antony's army as it fled to Armenia. Eventually, the greatly weakened force reached Syria. Antony lured Artavasdes II into a trap with the promise of a marriage alliance. He was taken captive in 34 BC, paraded in Antony's mock Roman triumph in Alexandria, Egypt, and eventually executed by Cleopatra VII of the Ptolemaic Kingdom. Antony attempted to strike an alliance with Artavasdes I of Media Atropatene, whose relations with Phraates IV had recently soured. This was abandoned when Antony and his forces withdrew from Armenia in 33 BC; they escaped a Parthian invasion while Antony's rival Octavian attacked his forces to the west. After the defeat and suicides of Antony and Cleopatra in 30 BC, Parthian ally Artaxias II reassumed the throne of Armenia. Peace with Rome, court intrigue and contact with Chinese generals Following the defeat and deaths of Antony and Cleopatra of Ptolemaic Egypt after the Battle of Actium in 31 BC, Octavian consolidated his political power and in 27 BC was named Augustus by the Roman Senate, becoming the first Roman emperor. Around this time, Tiridates II of Parthia briefly overthrew Phraates IV, who was able to quickly reestablish his rule with the aid of Scythian nomads. Tiridates fled to the Romans, taking one of Phraates' sons with him. In negotiations conducted in 20 BC, Phraates arranged for the release of his kidnapped son. In return, the Romans received the lost legionary standards taken at Carrhae in 53 BC, as well as any surviving prisoners of war. The Parthians viewed this exchange as a small price to pay to regain the prince. Augustus hailed the return of the standards as a political victory over Parthia; this propaganda was celebrated in the minting