Shammaites, as a sect of Judaism, are followers of Shammai, they are considered "hard-liners" akin to the zealots in that they believe that an earthly Messiah will free Israel from Roman oppression and that the "job of the truely righteous to give God a helping hand even through violent revolution".
Paul even states "exceeding zealus for the traditions of my fathers..." (Galations 1:13-14)
Thus they are Jewish fundamentalists who are willing and able to use violence in a "holy war" against "pagan" oppressors.
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