The Parthia was stolen by Adrah, and used to conquer the continent of Archanea. Upon the founding of the Kingdom of Archanea, the Partia was dubbed a Regalia and subsequently passed down through descending generations of Archanean royalty.
During the War of Darkness, Nyna presents Parthia to Marth in Chapter 12 (Chapter 10 in Book 1 of Mystery of the Emblem) after he successfully wrests control over the royal palace of Archanea from Volzhin's forces.
During the War of Heroes, Parthia appears in the possession of Jeorge in Chapter 8. Speaking to him with Gordin will convince him to harden his resolve to defect to Marth's army.
Parthia is an ancient country that once existed in the southwestern part of Asia. Becoming a powerful empire around the 2nd century BC, it collapsed in the 3rd century AD. The Parthians were known to be very skilled in mounted archery.
Parthia is tied with Gradivus for the highest base Might of all non-magical ranged weapons in Awakening.
With the exception Mystery of the Emblem, Parthia has the passive effect of the Barrier staff, making it the only weapon in the game with a passive bonus that wears off after a certain number of turns.