Daniel 8:21

And the rough goat is the king of Grecia: and the great horn that is between his eyes is the first king.

Cross-reference

Daniel 8:5-7 records the goat attacking the ram — the vision that Daniel 8:21 interprets as Greece conquering Medo-Persia.

Daniel 11:3 Parallel

In Daniel 11:3, the same 'mighty king' of Greece appears — Alexander the Great, directly paralleling the goat's large horn.

Daniel 7:6 Parallel

In Daniel 7:6, the leopard beast with four wings and four heads represents Greece — the same kingdom as the goat in chapter 8.

Daniel 10:20 mentions the prince of Grecia — the same kingdom as the goat in Daniel 8:21, but in a spiritual warfare context.

In Zechariah 9:13, Greece (Javan) is judged by God — a different role than the conquering goat, but still the same nation.