Iranian kingdom symbol. It seems do not be old and originated from ancient persia. But lion is Iranian symbol for several thousands years.
There are in circle some other small symbol. Sun is always symbol of Mithraism(eligion of love) mountain is Damavand highest mountain in Iran and highest volcanic mountain in northern Hemisphere of earth.
right above is fravahar means sacred leader it is same with german fürher(leader)
above left is lion and sun and sword in his right hand. sun and lion both are originated for mithraism for several thousands years but sword was new for two hundred year in hand.
left below is a sacred sword symbol of shia religion. because this sword was belonged to Imam Ali vice and husband of Fatima, holy girl of mohammad
He is first and Grand Imam in shia and he is very very beloved in shia.
I do not know what is symbol of right below it seems to be a Dragon.
Dragon in Iranian mythology is very negative. It is not clear for me.
I think this symbol was taken as a model from European countries kingdom symbol specialy from Britain and Germany for two hundred years but small symbol inside is very ancient for Iranian perhaps for 7000 years old
by Mehrdad. Parsenews