The Bible already tells us who the first 4 kingdoms are. Daniel in chapter 2, 7and 8 is looking forward from his time, and in Revelation 13 Johns first beast is a look from his perspective going back. So the first 4 are Babylon, Media/Persia, Greece, Rome. Confirmed by history and the first 3 by Gabriel's own explanations.
Which brings us to the NT. Now what we must do is follow the clues already provided, starting from Daniel 2. The statue had no gaps...no breaks...no interludes between the various empires. It actually describes only 5 empires from beginning to the second coming. The fifth one being the composite of clay and iron. Thus the 5th empire is a co-mingling of Rome and whatever followed immediately after...that can only be the RCC, the little horn which grew from the head among the ten.
Now the beast of Revel. 13 is another composite. Same empires, but still present in the beast. A future beast , but comprising attributes of past empires, Babylon, Media/Persia, Greece, and Rome. This we all know can be none other than the RCC, which indeed as a religious organisation, and a civil entity, has the attributes of those pagan powers in the mixture of her doctrines and practices.
The seven heads are a part of the same beast. Therefore they form one and the same empire, but are different aspects or powers within it, at times concurrent, at times chronological, but most certainly in many aspects one and the same. But what s different is that the NT powers are predominantly spiritual with but have inherited the ancient practice of church/state union. In the OT they were predominantly secular with religious overtones, in the NT the other way around. First the RCC. Predominantly religious, but with a civil aspect in that it is a church state union. Other world powers of NT times thus far is communism. Predominantly atheism, with church/state union. It is well accepted that modern atheism started with the French revolution, and grew from there. The French revolution was a spiritual revolution against the prevailing religious tyranny of Rome. It eventually engendered political support and power, and became a world wide empire that greatly challenged Christ's church.
Which leaves one more head to explain. that is yet to come, and it is the one which will shortly support the Vatican in her goal of worldwide dominion, and the introduction of false worship, and the mark of the beast. This is revealed as a beast in her own right, the second beast of Revel. 13, and is I believe apostate Protestantism, which I think will be demonstrated by a church/state union in America. When the Protestant churches unite with the state and enforce here dogmas on the people, she will have then formed a mirror image of the first beast, the papacy. They will work together to enforce global religious servitude to the dogmas and canons of the Roman church.
Babylon...............]
Media/Persia.......]________ Localized literal powers............]
Greece................] ]
Pagan Rome.......] ]____ All sharing the main principle of paganism...church/state union
Papal Rome....................] ]
Atheism/Communism.......]_____ Global spiritual powers......]
Apostate Protestantism...]
