Daniel had remarkable visions about the future, and this chapter is no less remarkable. An angel reveals to Daniel political and spiritual details about the future for hundreds of years, which quite specifically came to pass. God knew what the future held and information like this was able to assist the HIgh Priest of Jerusalem in future years to not resist Alexander the Great, but to cooperate with him. But after Alexander came Antiochus IV - of who the books of Maccabees mention. He was a nasty Tyrant who tried to force the Jews into being Greeks rather than following the Lord. Daniel was shown it in advance of when it happened.