How long the dominion of the Scyths endured is a matter of great uncertainty.

It was no doubt the belief of Herodotus that from their defeat of Cyaxares to his treacherous murder of their chiefs was a period of exactly twenty-eight years.

During the whole of this space he regarded them as the undisputed lords of Asia.

It was not till the twenty-eight years were over that the Medes were able, according to him, to renew their attacks on the Assyrians, and once more to besiege Nineveh.

But this chronology is open to great objections.