Zoroastrian tradition divided the sacred fires among the three classes of Sasanian society. Adur Farnbag belonged to the priests. Adur Burzen-Mihr was linked to the farmers. Adur Gushnasp served the arteshtaran -- the warrior class to which the Sasanian royal dynasty itself belonged. This was the fire before which kings humbled themselves before ascending the throne. Its temple stood in the city of Shiz, in the province of Adurbadagan, at the site now called Takht-e Soleyman. The identification became certain when archaeologists found a Sasanian-era seal there engraved with the words "High-priest of the house of the fire of Gushnasp." The fire was not mentioned in early Sasanian records, suggesting it was brought to this site sometime in the late 4th or early 5th century. But once established, it became inseparable from the legitimacy of the dynasty.

The first recorded royal patron was Bahram V, the Sasanian shah who ruled in the early 5th century. He celebrated Nowruz and Sadeh at the temple and entrusted the high priest with the delicate task of converting his Indian wife. Khosrow I visited the fire before launching military expeditions, seeking divine sanction for war. He also showered the temple with wealth drawn from the tribute that the Byzantine Empire paid the Sasanians. Byzantine and Islamic sources alike remarked on the immense riches accumulated at Adur Gushnasp -- a treasury fed by royal patronage, private devotion, and the steady flow of golden eyes and other votive offerings from believers seeking health, wisdom, and fortune for their children.

In 623 or 624, the Byzantine Emperor Heraclius struck deep into the Sasanian heartland during the long Byzantine-Sasanian War of 602-628. His army reached the temple of Adur Gushnasp and sacked it. The attack was both military and symbolic -- extinguishing the warrior class's sacred flame was an assault on the spiritual foundations of the Sasanian state. But the Iranians managed to save the fire itself, carrying it away before the Byzantines could quench it entirely. The apocalyptic Middle Persian text Zand-i Wahman Yasn may preserve a memory of this trauma: "They will remove Adur Gushnasp from its place... on account of the devastation of these armies, Adur Gushnasp will be carried to Padishkhwargar." The temple was quickly rebuilt and the fire restored. Heraclius had damaged the structure, but the flame endured.

The Arab conquest of Persia in the 7th century did not immediately destroy Adur Gushnasp. The fire continued to burn through the early Islamic period, tended by Zoroastrian priests whose community shrank generation by generation. Persecution intensified gradually. By the late 10th or early 11th century, the fire that had burned for at least six hundred years was most likely quenched for the final time. Not long after, a local Muslim ruler dismantled what remained of the temple and used its stones to build a palace on the hilltop. The sacred fire of the Sasanian warriors -- fed by the tribute of Byzantine emperors, the gold of believing pilgrims, the devotion of kings -- ended not with a dramatic raid but with a slow fading, as the last priests departed and the last embers cooled into ash.