Daniel 7:6-7, 23

After this I kept looking, and behold, another one (the Greek Empire of Alexander the Great), like a leopard, which had on its back four wings like those of a bird; the beast also had four heads (Alexander’s generals, his successors), and power to rule was given to it. [Dan 2:39; 8:20-22] After this I kept looking in the night visions, and behold, [I saw] a fourth beast (the Roman Empire), terrible and extremely strong; and it had huge iron teeth. It devoured and crushed and trampled down what was left with its feet. It was different from all the beasts that came before it, and it had ten horns (ten kings). [Dan 2:40-43; 7:23]

“Thus the angel said, ‘The fourth beast shall be a fourth kingdom on earth, which will be different from all other kingdoms and will devour the whole earth and tread it down, and crush it.