The 2nd and 3rd of the four empires are again told of here in verses 3 and 4 (the second empire) and verse 5 (the third, the Grecian empire).
V.8 is after Alexander the Great dies (aged 32) the Grecian, his empire is divided among 4 of his generals.
V.9-12 A man called Antiochus Epiphenes is the “little horn.” He lived during the silent years between the Old and the New Testament.
V.17, 19 Refers to the future.
V.23-25 Also are future. The Prince of Princes is the Lord Jesus.