28 The golden head of the image and the lioness denoted the Babylonians; the shoulders and arms of silver, and the bear, represented the Persians and Medes; the belly and thighs of brass, and the leopard, meant the Greeks, who held the sovereignty from Alexander's time; the legs of iron, and the beast dreadful and terrible, expressed the Romans, who hold the sovereignty at present; the toes of the feet which were part clay and part iron, and the ten horns, were emblems of the kingdoms that are yet to rise; the other little horn that grows up among them meant the Antichrist in their midst; the stone that smites the earth and brings judgment upon the world was Christ.
Source: The Antichrist (New Advent)