The second of the two middle kingdoms (kingdom three of the vision in chapter 7) is now introduced. This all agrees with the dream of chapter 2 and the vision of chapter 7, but we are pointed to new symbolism and a few extra details.
This prophecy was given more than 200 years before the events happened. As you read the details of Daniel’s vision, you understand how it is that unbelieving scholars have always made up their minds that the Book of Daniel must have been written far later than the Bible places it. They don't believe in prophecy, and prophecy couldn't be anything like as accurate as this. As with the miracles of Christ which could not be denied but which his enemies attributed to Beelzebub, so the great accuracy of the prophecies of Daniel cannot be denied and the detail of future events is extraordinary, and therefore the enemies of Scripture are forced to claim that the book was written long after these events occurred and is not genuine prophecy. But that is just speculation and unbelief. Archaeological discovery has now done much to silence the critics.