'King of Kings' in the Bible

Artaxerxes, king of kings, to Ezra the priest, a scribe of the Law of the God of Heaven, perfect peace, and now:

For so says the Lord Jehovah: Behold, I will bring Nebuchadnezzar king of Babylon on Tyre, a king of kings from the north, with horses and with chariots and with a company of horsemen, and many people.

You, O king, are a king of kings. For the God of Heaven has given you a kingdom, power, and strength, and glory.

For He in His own time will reveal who is the blessed and only Potentate, the King of kings and Lord of lords,

These will make war with the Lamb, and the Lamb will overcome them. For He is Lord of lords and King of kings. And those with Him are the called and elect and faithful ones.

And He has on His garment, and on His thigh a name written, KING OF KINGS AND LORD OF LORDS.