The “Beasts” refer to specific kingdoms God permits to rule in human affairs at various points in history. The first three kingdoms were the Babylonian empire, the Medo-Perian Kingdom, and the Greek Empire under Alexander the Great. Acts 4 and 5 introduce us to the Terrifying Beast and the “Ten Horn Beast”, which actually are the same nation/kingdom at different points in the unfolding history of the world. The clear explanation is this empire refers to the Roman Empire, which eventually lost control of the world, only to reemerge at a future point of human history in the form of a 10 nation-confederacy. And in the era of the 10 Horns, eventually one of the leaders and countries will emerge that takes over the world.