After the execution of Naudar the throne remains for a while vacant, his sons Tús and Gustaham being considered unworthy to succeed. Zav, by the advice of Zál, is made Sháh. The war against Afrásiyáb continues, and the sufferings of both armies are aggravated by drought and consequent famine. Both sides become eager for peace, which is successfully negotiated, rain falls and Zav dies.

Zav is described in the Sháhnáma as the son of Tahmásp and descended from the race of Farídún. In the Bundahish he is said to be the grandson of Naudar.* Zav is mentioned in the Zandavasta: “We worship the Fravashi (i.e. the immortal prin­ciple) of the holy Uzava, the son of Túmáspa.”*

The passing over of Tús and Gustaham, the sons of Naudar, on the express ground of their unfitness, as not being possessed of the divine Grace of sovereignty, seems to find its justification in what we learn of their characters later on, at all events in the case of Tús, who is described as being hot-headed, revengeful, and a brave but unsuccessful general. Gustaham almost drops out of the poem and his place is taken by another hero of the same name, Gustaham the son of Gazhdaham—the castellan of the White Castle.

Tús is represented as always resentful of the slight put upon him; it induces him to oppose the accession of Kai Khusrau, and subsequently to make the unprovoked attack which results in the death of Farúd, that Sháh's brother.

In the terms of the treaty of peace between Zav and Afrásiyáb, which make the Jíhún the boundary between Írán and Túrán, we have the beginning of much geographical confusion in the Sháhnáma. The Aras was really meant.*

Drought and famine are frequent phenomena in the table-land of Írán.