"Thus saith Cyrus king of Persia, The Lord God of heaven hath given me all the kingdoms of the earth; and He hath charged me to build Him an house at Jerusalem, which is in Judah" (Ezra 1:2).
It is noteworthy that the words of this verse are almost the same as in the last verse of II Chronicles. This is an indication that Ezra the scribe (who wrote the book of Ezra) was also the compiler and editor of the two books of Chronicles.
Even more noteworthy is the fact that the great emperor Cyrus seemed to acknowledge that the God of Israel was not just a tribal god, as many have claimed, but the Lord God of heaven -- that is Jehovah Elohim -- recognizing Him as both Creator and Redeemer of the world. The Persians were largely followers of Zoroaster but his religious system did bear some resemblance to the true monotheism of Israel.
But Cyrus had been called, and even named, by God, long before He was born (Isaiah 44:28-45:6). When he conquered Babylon, the prophet Daniel was there (Daniel 6:28). The Jewish historian, Josephus, wrote that Daniel even became prime minister under Cyrus and was able to read Isaiah's remarkable prophecy to him, thus influencing him to send the Jews back to Jerusalem.
There have also been other Gentile rulers who acknowledged God, even before Christ came. Nebuchadnezzar of Babylon, once hating God, finally was forced to confess that He was "the most High" and "King of heaven" (Daniel 4:34,37). Another was the Queen of Sheba, who recognized "the Lord thy God" (again Jehovah Elohim, I Kings 10:9). Then there was the king of Nineveh and Assyria, who believed in God at the preaching of Jonah (Jonah 3:6-10). In fact in the ages to come "the kings of the earth" will all "bring their glory and honor" to the Lord in the holy city (Revelation 21:24). HMM