The Battle of Hormozdgan was the climactic battle between the Arsacid of the Parthian Empire and the Sasanian dynasties that took place on April 28, 224. The Sasanian victory broke the power of the Arsacid dynasty, effectively ending almost five centuries of Parthian rule in Iran, and marking the official start of the Sasanian era.
Ardashir I- also known as Ardashir the Unifier was the founder of the Sasanian Empire. After defeating the last Parthian shahanshah Artabanus V on the Hormozdgan plain in 224, he overthrew the Parthian dynasty and established the Sasanian dynasty. The chief secretary of the deceased Arsacid king, Dad-winded, was afterward executed by Ardashir I. Thenceforth, Ardashir I assumed the title of shahanshah ("King of Kings") and started the conquest of an area which would be called Iranshahr (Eranshahr).
Depicted here is Double Dinar of Ardashir I, struck at the Ctesiphon mint. The obverse of the coin depicts Draped bust of Ardashir right, wearing diadem and close-fitting headdress with korymbos and ear flaps, pellet behind the head with the legend "The divine Mazdayasnian King Ardashir, King of King of the Iranians". While the reverse shows a Flaming fire altar with two ornate supports, each tied with a diadem. With the legend "Ardashir's fire".
Image Source: Heritage Auctions