The different nations of Europe would try to mix in together; they would intermarry with one another; form political alliances; and so on. The royal families of the European nations constantly intermarried, over the centuries, for strategic political alliances. The kings and queens of Europe tried their best to “mingle themselves” time and again through the centuries. And they still try today! But the verse goes on to say that they would fail. The European nations did not permanently cleave to one another, despite all attempts to make them do so through the centuries! They have remained separate.
This is the clear teaching of Daniel chapter 2. And if we carefully examine Daniel chapter 7, we find that it simply speaks of the rise of the ten kingdoms in history (called “ten horns”), and of the Roman Papacy (“the little horn”) in the midst of them. It certainly shows that the ten kingdoms would give their allegiance, spiritually, to the Papacy; but not a word is spoken about a time coming when they would all successfully and completely unite as one, politically! History is full of their attempts to do so – but attempting is not the same as succeeding!
As for what the book of Revelation says about the ten horns: over and over, in chapters 12, 13 and 17, it speaks of the ten horns. It states that the ten horns serve the Roman Papal beast. But it does not prophesy of a time when the ten would successfully form a gigantic political union of European states at the end of time! Not a word is said about such a thing.
There is, however, one place in Revelation 17 which may, at first glance, appear (more so than the other texts concerning the ten kings) to be speaking of an end-time union of European states, and this is Rev. 17:12-17. Let us examine this text more closely, to see what it is really teaching.
V.12 says, “And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast.”
The ten horns were the barbarian kingdoms into which the western Roman Empire broke up in the fifth century AD. John was given this vision in the first century AD, so they had not come into existence when he wrote; which is why the verse says they “have received no kingdom as yet”.
As stated previously, there were sometimes more than ten, and sometimes less, because of wars between them, merges, shifts in power, the fall of some of the kingdoms, the rise of others, etc. But ten was their original number, and ten was their average number through the centuries.
V.12 goes on to say of these ten kingdoms that they “receive power as kings one hour with the beast.” And because of these words, Futurist interpreters of prophecy wrongly assume that at some point in the near future, the western European countries will successfully unite with one another (the EU, they believe), and with the supposed future Antichrist. However, not only do these words say absolutely nothing about a gigantic European union of states, but this prophecy was in fact fulfilled in the past!
While the Roman emperor reigned, the popes of Rome did not rise to great power over the whole empire. They had to wait until the empire and its emperor, which prevented the Papacy rising to supreme power, was removed; which is precisely what Paul prophesied about, in 2 Thess. 2:6-8. When the barbarian kingdoms destroyed the empire and removed the emperor, in the late fifth century AD, then it was that the Papal beast could rise to its position of supreme power! And it did.
Therefore, just as v.12 says, the ten kings received power with the Papal beast.