'Diadems' in the Bible

And there was seen another sign in heaven: and behold, a great red dragon, having seven heads and ten horns, and upon his heads seven diadems.

and he stood upon the sand of the sea. And I saw a beast coming up out of the sea, having ten horns, and seven heads, and on his horns ten diadems, and upon his heads names of blasphemy.

And his eyes are a flame of fire, and upon his head are many diadems; and he hath a name written which no one knoweth but he himself.