Some words are mysterious and have a very long history, Kian is one of them, this Persian word certainly means "King" but differs from Shah, it seems to possible for Iranian peoples to hate their Shah but not their Kian, we should always defend our Kian, that is our most important thing to preserve, it is really difficult to explain what this word exactly means, Kian is something or someone who makes us united under one name, father is Kian-e Khanevade (Kian of Family) and King or leader is Kian-e Keshvar (Kian of the country).
There was a semi-mythological dynasty named "Kianian/Kianid", almost all Persian and even non-Persian kings of Iran considered themselves descendants of this dynasty, I think the most important thing was "Kiani Crown", Ferdosi, Iran's national poet, says about Arab invaders in Shahnameh:
Ze shireh shotor khordano susmar
Arab ra be jaii reside ast kar
Ke Tajeh Kiani konad arezu
Tofu bar to ey charkheh gardun tofu
From eating camel milk and lizard,
Arab got so bold, that now,
Dreams of capturing the Kiani Crown
Fie on you, o fate! fie on you!