The ram that you saw possessing the two horns stands for the kings of Media and Persia.

Dan. 8:15-22.

18. After the downfall of what world power did the vision apply, who were the symbolic horns of the “ram,” and who was the symbolic single horn of the “goat”?

¹⁸ This prophecy begins to apply, therefore, after Darius the Mede and Cyrus the Persian brought about the downfall of Babylon in the autumn of the year 539 B.C.E. and the Medo-Persian Empire was established as the Fourth World Power of Bible history. This Empire, which grew to greater size than that of Babylon, eastward and westward and southward, continued its world domination from 539 to 331 B.C.E. (Dan. 5:1–6:28; 11:1, 2)