The Shâhnâmeh (Book of Kings) is major epic work of persian poetry "Ferdowsi Tousi". “Bayasanghori Shâhnâmeh” was made in 1430 for Prince Bayasanghor (1399-1433), the grandson of the legendary Central Asian leader Timur (1336-1405).
Zahhāk (in Persian: ضحّاک/ذهّاک), In Middle Persian he is called Dahāg or Bēvar-Asp, the latter meaning "[he who has] horses". In Zoroastrianism, Zahak (going under the name Aži Dahāka) is considered the son of Angra Mainyu, the foe of Ahura Mazda.
King Key Kavus was captured and blinded by divs in Mazandaran. Rostam set him free, but to cure his blindness he needed the White Div’s liver. The battle with the White Div in its lair — the cave shown in section here — was Rostam’s seventh and final Peril.