The Book of Daniel was written by the prophet Daniel, who was taken into captivity when he was 15 and distinguished himself in wisdom and spiritual leadership. This book plays a large part in interpreting the prophecies in Revelation, and its key verse is "And in the days of these kings shall the God of heaven set up a kingdom, which shall never be destroyed: and the kingdom shall not be left to other people, but it shall break in pieces and consume all these kingdoms, and it shall stand for ever," found in 2:44. The key truth in the book is God reigns supreme, and it was written in the 6th Century B.C. during the Babylonian captivity.