Erato (flourished 1st century BC and 1st century AD) was a Princess, queen of Armenia and the last member on the throne of the Artaxiad Dynasty. She was the daughter of Armenian King Tigranes III and half-sister/wife of King Tigranes IV. In the centuries before Christianity, incestuous marriages were common at Hellenistic courts in order to preserve the purity of the royal blood. Her image appears on an ancient coin which currently keeps at the National Library in Paris. She was the only Armenian sovereign to ascend to the throne three times. Erato reigned along with her brother Tigranes IV from 8 to 5 BC, 2 BC to 2 and later with Tigranes V, 6 to 11. Roman Emperor Augustus sent Tiberius to appoint Artavasdes III of Armenia as King of Armenia, who was a cousin of Tigranes IV and Erato. Tigranes IV and Erato instigated a civil war with the aid of King of Phraates V of Parthia.
The Parthian king soon ceased his support in order to avoid a full scale war with Rome. Gaius Caesar was sent to Armenia to stop the civil war, prior to his arrival Tigranes IV was murdered during one of the disturbances and the Armenian throne was bestowed upon Ariobarzanes II, a Mede by origin. Ariobarzanes II was killed in an accident and Augustus nominated Ariobarzanes II's son, Artavasdes IV, as the new King. The Armenian population grew weary of foreign Kings and Augustus revised his policy by giving the throne to Tigranes V, an Artaxiad of unknown affiliation. The Armenian nobles, unsatisfied with Tigranes V, rebelled and restored Erato with Tigranes V to the throne. They were overthrown under unknown circumstances in 11, after which the Artaxiad Dynasty became extinct. Augustus decided to keep Armenia as a vassal kingdom instead of annexing it to the Empire. In 12, Vonones I of Parthia was appointed as King of Armenia by Augustus.