We know that the final kingdom is Christ's kingdom and the New, Jerusalem, Heaven as most say. But, according to this prophecy, we must now be living in the fourth kingdom, the latter part, mixed with iron and clay.
I challenge you to name the kingdom (It's not a mystery anymore, and i'm not promoting a new idea because the third kingdom was clearly Greece), and challenge you to explain how this is possible based on History. And I will tell you you're going to have to reject.....