Musa (also spelled Mousa), also known as Thea Musa, was a ruling queen of the Parthian Empire from 2 BC to 4 AD. Originally an Italian slave-girl, she was given as a gift to the Parthian monarch Phraates IV by the Roman Emperor Augustus. She quickly became queen and a favourite of Phraates IV, giving birth to Phraataces (Phraates V). In 2 BC, she had Phraates IV poisoned and made herself, along with Phraates V, the co-rulers of the empire. Their reign was short-lived; they were forced to flee to Rome after being deposed by the Parthian nobility, who crowned Orodes III as king. Musa is the first of only three women to rule as monarchs in Iranian history, the others being the two 7th-century Sasanian sisters Boran and Azarmidokht. Additional women, Rinnu, Ifra Hormizd and Denag, ruled only as regents of their sons and not as full monarchs in their own name. Rise to power Musa was an Italian slave-girl who was given to the Parthian monarch Phraates IV as a gift by the Roman Emperor Augustus. Phraates IV received her around the time a treaty was made in 20 BC, whereby he received his kidnapped son in exchange for several Roman legionary standards captured at Carrhae in 53 BC, and the surviving Roman prisoners of war. The Parthians viewed this as a small price to pay to regain the prince. Emma Strugnell (2008) has suggested that Augustus may have sent Musa in an attempt to obtain information or influence the Parthian king to the advantage of the Romans. According to the Parchments of Avroman, Phraates IV already had at least four other queens at that time: Olennieire, Cleopatra, Baseirta and Bistheibanaps. Musa quickly became queen and a favourite of Phraates IV, giving birth to Phraataces (Phraates V) about 19 BC. Seeking to secure the throne for her son, she convinced Phraates IV in 10/9 BC to send his four first-born sons to Rome in order to prevent conflict over his succession.

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Musa (also spelled Mousa), also known as Thea Musa, was a ruling queen of the Parthian Empire from 2 BC to 4 AD. Originally an Italian slave-girl, she was given as a gift to the Parthian monarch Phraates IV by the Roman Emperor Augustus. She quickly became queen and a favourite of Phraates IV, giving birth to Phraataces (Phraates V). In 2 BC, she had Phraates IV poisoned and made herself, along with Phraates V, the co-rulers of the empire. Their reign was short-lived; they were forced to flee to Rome after being deposed by the Parthian nobility, who crowned Orodes III as king.