Kai Káús on ascending the throne abandons the path of wisdom. He invades Mázandarán and is taken prisoner, but is rescued by Rustam. He wars against the king of Hámávarán, whose daughter he marries, and is taken prisoner again, this time by treachery. Rustam again rescues him. Afterward he attempts to fly to heaven, and is a third time saved by Rustam. The poet then tells two episodic stories, that of the Seven Warriors, and that of Suhráb, in both of which Rustam takes a leading part. We next learn what evil came of the marriage of Kai Káús with the daughter of the king of Hámávarán as exemplified in the tragic tale of Siyáwush. The poet then tells how Rustam took vengeance on Afrásiyáb for the execution of Siyáwush, how Gív went to Túrán in quest of Kai Khusrau, the son of Siyáwush, and how Kai Khusrau became joint Sháh with Kai Káús.

Kai Káús appears in the Vedas as Kávya Ushaná, i.e. Ushaná the son of Kavi. He is said to have installed Agni (fire) as the high-priest of mankind, to have been the leader of the heavenly cows (the clouds) to pasturage, and to have wrought the iron club with which the god Indra sl??w the demon Vritra.*

The conception is therefore mythological. In the Zandavasta Kai Káús appears as Kavi Usa. “We sacrifice ??to Ver??thraghna,*

made by Ahura… He carries the chariot of the lords; he carries the chariot of the lordly ones, the chariots of the sovereigns. He carried the chariot of Kavi Usa.”*

With the exception of this reference to his attempt to fly to heaven the remainder of his legend is lost so far as the Zandavasta itself is concerned, but a brief summary of what it once contained is extant in the Dínkard,*

where we also find a strange story, of which no trace is to be found in the Sháhnáma, that Kai Káús possessed a wonderful ox, to whose judgment all disputes as to the frontier-line between Írán and Túráin were referred. As the decision was generally adverse to the Túránians they conceived the idea of beguiling Káús into slaying the ox, and succeeded in their purpose.*

The story is characteristic of Kai Káús, who is represented in the poem as a very imperfect character, and easily led astray by passion, wrong­headedness, and evil counsels.

According to the genealogy of the Bundahish, Káús was the grandson of Kai Kubád.*

Firdausí omits the intermediate genera­tion.

The length of the reign is the same in both cases, and the Bundahish places Káús' attempt to reach the sky after he had been on the throne for seventy-five years,*

and was, so to speak, at his meridian.