“Cyrus.” “Cyrus” is a proper name, unlike Ahasuerus, Xerxes, or Artaxerxes, which are all titles. Cyrus reigned over Persia for 30 years, from c. 559 to 530 BC. Isaiah prophesied during the reigns of Uzziah, Jotham, Ahaz, and Hezekiah, which would be at the most from 776 BC (the start of the sole reign of Uzziah) to 697 BC (the end of Hezekiah’s reign). It is unlikely that this prophecy of Isaiah was at the very end of his reign, and thus likely that this prophecy was given at least 150 years before Cyrus reigned. Foreknowledge of this type and accuracy can only be accomplished by God, which is why doubters say that this part of Isaiah could not have been written during the lifetime of Isaiah, but had to be written after Cyrus reigned and then adjusted to make it seem like a prophecy. But there is no real evidence that this prophecy was not written by Isaiah. This kind of historically verifiable prophecy is one of the reasons that we can believe that the Bible is the Word of God, not the words of humans.