is the receiver of the ring; so he could not be Ahura Mazda, either). Researchers long debated the identities of the figures in this relief but is now ascertained that Ardashir II receives the beribboned ring - symbol of royal investiture - from his predecessor Shapur II or Ahura Mazda. There may be a deliberate mixture of the iconography of both identities. The two main figures are standing on the fallen Roman emperor Julianus Apostata (361-363 AD). Ardashir played an important role in his defeat during the reign of Shapur II (309-379 AD). Exceptional within Sasanian art is the fact that this is a portrait, based on the image of Julianus Apostata as it appears on Roman coins. Ardashir II was installed as interim ruler, awaiting the coming of age of the royal heir Shapur III (383-388 AD). The fourth figure is the god Mithra who holds a barsum in his hands and stands on a lotus flower. He is the protector of oaths and is witness to this pact. Local beliefs and Persian folk tale interpreted the scene as the victory of the first Sasanian kings on Artabanus IV, the last king of the Parthian dynasty. The Mithra figure became the visual inspiration for representations of the prophet Zoroaster. The relief panel is approx. 4.07 m wide and 3.9 m high. Shapur II and Shapur III The smaller arch or iwan (Taq-e Bustan II) has, on the upper part of the back wall, two Pahlavi inscriptions identifying two royal figures as Shapur II (Shapur the Great) and his son Shapur III. They are shown facing each other. The arch's vestibule measures 6 x 5 x 3.6 meters. It has been suggested as having been built during the reign of Shapur III and some put the date of its completion at 385 AD. However, the royal crown of Shapur III does not agree with those on his coins and is closer to that of his predecessor Ardashir II. It has been argued that the texts represent an usurpation of Ardashir's relief by Shapur III. The translation of the inscriptions follows: Shapur II inscription : This is the figure of Mazda-worshipping Lord Shapur, the king of kings of Iran and Aniran, whose race is from the Gods. Son of Mazda-worshipping Lord Hormizd, the king of kings of Iran and Aniran, whose race is from the Gods, grandson of Lord Nersi, the