King Cyrus (the Great) of Persia was a huge player on the stage of history behind the second half of the book of Isaiah. The Isaiah community admired him for his acts of liberation and his spirit of reverence and tolerance of local traditions. The Cyrus Cylinder, a major artifact in biblical studies, gives us a window into Cyrus' image and policy in the late exilic and early postexilic era. This cuneiform text also gives the biblical historian helpful data for reconstructing the fall of Babylon to Cyrus and the Persian Empire and the period of the beginning of Israel's restoration. See Ezra 1:1-6; 6:1-5.
There is a neat WebSite on the Cyrus Cylinder, which contains a complete translation and some good discussion. To access all this, click here.
The Cylinder was discovered in 1879 and is now in the British Museum.