Excommunication also exists in Judaism- it's known as cherem, a word which literally meant "destruction". In Europe in the Middle Ages, excummunication could be instituted by any Beis Din, or local tribunal of rabbis, and it was a popular weapon against deviancy. The tribunal would send letters to other Jewish communities informing them of the ban, which forbade exchanging words or doing business with the excommunicated person, who would be unable to even buy food from other Jews. So cut off from Jewish contact, this person would be forced to convert to Christianity or he/she would die.

One typical cherem was the one pronounced on Baruch Spinoza. See The Anathematization of Baruch Spinoza.