"'Then I wanted to know the true meaning of the fourth beast, which was different from all the others and most terrifying, with its iron teeth and bronze claws - the beast that crushed and devoured its victims and trampled underfoot whatever was left. I also wanted to know about the ten horns on its head and about the other horn that came up, before which three of them fell - the horn that looked more imposing than the others and that had eyes and a mouth that spoke boastfully. As I watched, this horn was waging war against the saints and defeating them, until the Ancient of Days came and pronounced judgment in favor of the saints of the Most High, and the time came when they possessed the kingdom.'" NIV translation
Now, we are told the reasons that this dream troubled Daniel so much. First of all, this beast was unlike any that he had seen before while the others had at least resembled animals that he knew about. The second thing is that he saw the beast defeating the people of God which was also his people. If his dream was true, then, that would include him being devoured by the beast.
"'He gave me this explanation: "The fourth beast is a fourth kingdom that will appear on the earth. It will be different from all the other kingdoms and will devour the whole earth, trampling it down and crushing it. The ten horns are ten kings who will come from this kingdom. After them another king will arise, different from the earlier ones; he will subdue three kings. He will speak against the Most High and oppress his saints and try to change the set times and the laws. The saints will be handed over to him for a time, times and half a time."'" NIV translation
The Roman Empire was not defeated but was split in two with the western half based in Rome and the eastern half in Constantinople.The city would become the capitol of the Ottoman Empire which would dominate what we call the Middle East.
At the end of World War 1, the empire was broken up into ten pieces: Turkey, Syria, Lebanon, Palestine, Transjordan, Kingdom of Hejer, Sultanate of Nejd, Yemen, and the Arab States of the Persian Gulf (United Arab Emirates). The Kingdom of Hejer & the Sultanate of Nejd became a part of Saudi Arabia. We see that the saints will be handed over to the antichrist for a period of time that is generally called the first half of the Great Tribulation.