Jesus says the author of this book is Daniel (Matthew 24:15). Daniel was among the first captives of Israel taken to Babylon (Daniel 1). As a prophet of God many of his prophecies have come to pass, the rest will follow.
Daniel 2 describes the Lord as the “stone cut out without hands” filling the earth striking the kingdoms of the earth (V34-35) and setting up a kingdom that will never be destroyed and stand forever (V44).
In the prophecies of Daniel we find the key of interpretation for other prophecies especially concerning the first coming of Jesus and the tribulation which will come in the last days just before His second coming.
God used Daniel to keep His people on track by raising him up as a prophet but also a confidant of the Babylonian king (Daniel 3). Through the faithfulness of Daniel’s companions, God showed His Majesty, and the king praised God (V28).
But Nebuchadnezzar’s pride once more got the better of him (Daniel 4) so God taught him a lesson that as great a king as he was, God was going to drive him to live as an animal for seven years (V25) till he learned God was God and he wasn’t. Daniel called on the king to repent (V27). But he didn’t and suffered the humiliation his dream predicted. In the end, after he came to his senses, Nebuchadnezzar learned the lesson and praised God (V34-37).
But pride ran in the family and Nebuchadnezzar’s grandson, Belshazzar, lifted himself up against the Lord (Daniel 5:23) and saw the writing on the wall that God had numbered his days because he had been weighed and found wanting, and his kingdom would be divided (V25). That very night Belshazzar was slain and Darius the Mede received the kingdom (V30-31).
The officials in Darius’ kingdom didn’t like Daniel and conspired against him by having Darius make a decree that if anyone petitioned any god except the king that he should be thrown into the lions den (Daniel 6). Without thinking it through the king signed the order and Daniel was found to be praying to the God of heaven as was his habit and was cast into the lions den.
Displeased but unable to do anything about it, Darius hoped God would deliver Daniel. The next morning Darius found Daniel still alive and took him out of the den, cast the conspirators and their families into the den instead (V24) and made a decree that men must tremble and fear before the God of Daniel. And Daniel prospered in the reign of Darius and in the reign of Cyrus (V28).