Daniel 8:21

And the rough goat is the king of Grecia
Including all the kings of it, from Alexander to the end of the Grecian monarchy; or rather the kingdom of Greece, which began in him, and continued until it was destroyed by the Romans: this was signified by the rough or hairy goat, especially when Alexander was at the head of it, for his strength and prowess, his swiftness in his marches over rocks and mountains, his majesty and grandeur, and also his lust and uncleanness; (See Gill on Daniel 8:5): and the great host that is between his eyes is the first king;
this is Alexander, who, though he was not the first king of Macedon, his father Philip, and others, were kings before him; yet was the first king of the Grecian monarchy, which took place on the Persian monarchy being destroyed by him.