“a ram.” This is a picture of the Medo-Persian Empire. “A ram was a fitting symbol of the empire, for according to Ammianus Marcellius (10.1; fourth century AD), the Persian ruler carried the gold head of a ram when he marched before his army” (Stephen Miller; New American Commentary).

“high.” Many versions read “long,” but the text reads “high” and thus makes a cultural reference to being exalted and honored. The horn that was “higher” than the other was more exalted and honored (and powerful) than the other.