The poet tells the history of the first ten Sháhs of Írán, describes the progress of the world from barbarism to culture, and the invention of the arts and sciences, and finally how the Grace departed from the Pishdádian Dynasty through the unworthiness and degeneracy of its representatives.

The word Pishdádian, the name given to the Sháhs of the first Iránian Dynasty, means those of the old law or original dispensa­tion. Zoroastrianism was built upon an older foundation of nature-worship, to which it bears some such relation as the New Testament bears to the Old. One of the gods of the elder faith— Ahura, the Asura of India—became the supreme deity, Ahura Mazda, of the new dispensation, and the Urmuzd of the Sháhnáma. Accordingly Gaiúmart, the first Sháh in the poem, is expressly recognised in the Zandavasta, as the first worshipper of Urmuzd.* Húshang, the second Sháh, institutes the worship of fire—a characteristic feature of Zoroastrianism. Urmuzd in the Zanda-vasta makes a covenant with Yima, the fourth Sháh, and tries to persuade him to undertake the part of lawgiver afterwards taken by Zoroaster, but Yima through modesty declines.

Zoroastrianism therefore in a sense existed before Zoroaster, with whose advent the Zandavasta ends; hence there is less anachronism than might be supposed in the allusions, often made in the earlier parts of the poem, to fire-worship, the Zandavasta, and similar matters. Zoroaster was the first recipient of the complete revelation.