As soon as life, a creation of Ahuramazda, left a person, the Death-demon, a creation of Ahriman, defiled the body and any action which brought it into contact with the fire, water, and the earth, resulted in the defilement of these holly creations.
It was on this account that the Zoroastrian religion forbade inhumation or cremation of the corpse, or the casting of it into water; instead, it enjoined exposure. The corpse was placed on a rock, hilltop, or in a remote area in the desert. Thus exposed under the sun, the flesh was removed by birds or animals of prey within hours, and the bones were cleansed. The purified remains were then placed in a clay or rock-cut astodan «bonereceptacle», i.e. an ossuary.
The Achaemenid kings were mummified and beginning with Darius the Great, were placed in rock-cut tombs. Two such tombs are cut into the «Royal Hill» of Persepolis; one is at the north overlooking the northeastern corner of the Terrace, and the other is at the south, overlooking the southeastern corner of
the Terrace. These tombs are attributed to Artaxerxes II (404- 358 B.C.) and to Artaxerxes III (358-38 B.C.); the southern tomb which has labels identifying «throne-bearers» is believed to be that of Artaxerexes II and that on the north is attributed to Artaxerexes III. A third tomb, left unfinished, is cut into the rock to the south of Persepolis; this was formerly attributed to the last Achaemenid king, Darius III (336-30 B.C.), but the attribution is doubted in more recent studies.
The facade of the Royal Tombs is carved in the shape of a cross with limbs of equal length (at Persepolis the lower section has not been hewn out of the rock). The upper limb is sculptured with a ritual scene; the king clad in the «Persian» costume, stands on a three-stepped plinth, facing the Royal Fire burning upon a tall altar which also rests upon a three-stepped plinth. (Each Persian king kindled a fire at his coronation. This was the symbol of his reign and was extinguished only when the king died). He holds a bow (the national weapon of the Iranians) in one hand, and extends his other hand with open palm towards the holy flames in a gesture of adoration.