I will be like the Most High (comp. Isaiah 47:8). It is a mistake to say that "the Assyrians gave the name of God to their monarchs" (Kay), or, at any rate, there is no evidence that they did. Nor does any king, either Assyrian or Babylonian, ever assume a Divine title.
There is a marked difference in this respect between the Egyptian and the Assyro-Babylonian religions. Probably Isaiah only means that Babylonian monarchs thought of themselves as gods, worked their own wills, were wrapped up in themselves, did not in heart bow down to a higher Power.