Kayánid in the ancient Iranian sacred tradition were a dynasty of “visionary leaders” who governed and ruled over the Aryans before their entry into the world stage as the greatest Empire of the ancient world.
Kayánid is the plural of Kay, and comes from the Avestan kavá “priest ruler” or “philosopher king.” Kaváis were great rulers/kings renowned for their gift of foresight/vision. They were the great leaders/kings of men in the Avestan lore.
Avestan kavá goes back to proto Indo European speech, and is rooted in the reconstructed Indo European *keuh “to perceive.” It comes in the same sense of “perceive, having visions of ” in the poetic gathas, See Yasna 33.6, 1st rhymed verse line.
Kavá is a cognate of Vedic kaví Lydian kawe “visionary poet/priest,” Latin cavaeō “take heed” Old Church Slavonic čujo “note,” čudo “wonder,” Old English hāwian “look at.”
Avestan kavá– has a perfect identical cognate in Lydian kawe-, making it not only Indo-European, but Proto-Indo-European, (See Didier Calin.)
In the Rig Veda, the term kaví refers to poets and priests, and is also a term applied to the gods, gift of foresight and visions. The kavís compose their poetry by the power of their thoughts mati and send their “poetic visions” dhī into the divine world.
In the Avesta, the kaváis were entrusted with the guardianship of xᵛarənah or farnah. Farnah means “fiery splendor, divine luminosity, god energy.” Farnah represents a link between the energy of light/blazing fire in connection with kingship and the life force.
Farnah or xᵛarənah comes from a Scytho-Sarmatian and Alan background, and is a cognate of Ossetic farnä and farn “a magic force or power of fiery nature.”
The Avestan Yashts talk of the fiery splendor of kaváis (kavaæm xᵛarənö), of the fiery splendor of the Aryans (airyanəm or airyanąm xᵛarənö) and farnah the fiery splendor of daæná, the “luminous vision” of the Immortals or the Zoroastrian religion.
In the Avestan lore and the poetic gathas, most of the kaváis have forsaken their gift of foresight, their wondrous, superior wisdom/craft ḵratü, and have gone over to the realm of darkness, greed and corrupted power.
However, FEW have stayed faithful/true to the farnah or xᵛarənah of the noble ones and the luminous vision of Immortals such as Kavá Vištáspö, who was the great patron of the Aryan Prophet Zarathûštrá, and whose name comes in connection with the Magian fellowship and dominion/kingship in the gathas, See Yasna 51.16, 1st rhymed verse line.
In the beautiful Yašt 19 of the Avesta, the farnah or xᵛarənah of the kaváis is closely associated with cosmic order, new dawn/day and the fresh creation of the worlds, faršö kereitî.
This fiery energy that belonged/belongs to Ahûrá Mazdá, his Auspicious, brilliant Immortals, and the yazatás or “adoreable god-beings” in both worlds when they established the creations, shall make the existence fraša splendid/new again (Yašt 19.10-24.)
According to the sacred Zoroastrian lore, Kavá Siāwaxš built the Kang castle (Kang–dæž) by the fiery splendor of kaváis (kavaæm xᵛarənö.) From the stronghold of this castle the rule of the Aryans, the victory of daæna Zoroastrian religion or “luminous vision” of the Immortals will be commanded at the end of times, before the setting in of an eternal spring, and the fresh, new age of the god-men.