Beasts of Myth and Fable #2

I rather enjoyed this one, as it's just as much about the inspiration for the beast as it is about the beast itself.

Regal am I, lord of den and roost:

Bird of empires and beast of kings,

Creature of two worlds loosed

To guard thy golden things.

My father prowls in vast savannah

And hunts the wild gazelle.

His roar is like fierce thunder

And all beasts flee him pell-mell.

My mother is queen of highest aerie

And flies on a standard imperious.

She screams of courage and victory

With her talons bloody and vicious.

What am I?