The little horn (Daniel 8:9) was a fierce king. This description fits Antiochus IV, who was a ruler from the Seleucid dynasty from 175 to 163 BC (compare Daniel 11:21–45). He called himself "Epiphanes," which means "The Manifest Presence [of God]." But many people, including Jews, mockingly called him "Epimanes," which means "Mad Man."
By desecrating the temple and Jewish worship (Daniel 8:11–12), Antiochus tried to destroy Judaism and unify his kingdom under Hellenistic culture. Some Jews were influenced by Hellenism and adopted Greek customs.