---
title: "反ユダヤ主義とは何か：定義と歴史"
description: "反ユダヤ主義とは、ユダヤ人に向けられる偏見や憎悪であり、固定観念、陰謀論、排除、暴力として現れます。その形は何世紀にもわたり、宗教上の中傷から人種思想、国家による迫害へと変化してきました。"
url: "https://ja.hasbara.co.il/resources/antisemitism/overview"
type: "resource-page"
locale: "ja"
categories: ["反ユダヤ主義"]
---

# 反ユダヤ主義とは何か：定義と歴史

*反ユダヤ主義とは、ユダヤ人に向けられる偏見や憎悪であり、固定観念、陰謀論、排除、暴力として現れます。その形は何世紀にもわたり、宗教上の中傷から人種思想、国家による迫害へと変化してきました。*

Antisemitism is prejudice against or hatred of Jews. It appears in claims that Jews are collectively dangerous or disloyal, in conspiracy theories about Jewish power, and in actions that exclude or attack Jews because they are Jewish. The Holocaust was its most catastrophic modern expression: Nazi Germany and its allies murdered six million European Jews between 1933 and 1945.

This page follows the history from ancient and medieval anti-Jewish ideas through modern racial antisemitism and the Holocaust. Related pages explain [how antisemitism works in daily life and public policy](https://ja.hasbara.co.il/resources/antisemitism/expressions-of-antisemitism), [how Holocaust denial distorts the record](https://ja.hasbara.co.il/resources/antisemitism/holocaust-distortion-and-denial), and [when anti-Israel expression crosses into antisemitism](https://ja.hasbara.co.il/resources/antisemitism/the-new-antisemitism).

## From ancient prejudice to medieval myths

Anti-Jewish prejudice predates the modern word. The United States Holocaust Memorial Museum traces European anti-Jewish ideas to antiquity and early Christianity. In the first millennium of the Christian era, some church leaders promoted collective blame of Jews for Jesus’s death and treated Jewish refusal to convert as evidence of disloyalty. Those teachings circulated in societies where Jews were a minority and helped make religious difference a basis for exclusion.

A particularly dangerous falsehood was the blood libel: the fabricated accusation that Jews murdered Christian children for ritual purposes. The first recorded medieval European case cited by the Museum concerned William of Norwich in 1144. In 1475, Jews in Trent were tortured into confessions and executed after a child’s death was falsely blamed on them. Such accusations turned rumor into violence and were revived in later centuries. The [Museum’s history of blood libel](https://encyclopedia.ushmm.org/content/en/article/blood-libel) documents these cases and their consequences.

## Modern prejudice changes its vocabulary

As European societies became more secular, anti-Jewish hostility did not simply disappear. Political movements increasingly framed Jews as a racial or national threat, even when Jewish families had lived in a country for generations. The word “antisemitism” itself dates to the late nineteenth century; the underlying prejudice was much older. Across these eras, the recurring device was to assign Jews collective guilt for social problems rather than judge people as individuals.

In Nazi Germany, those ideas became government policy. After Adolf Hitler became chancellor on January 30, 1933, the regime organized a nationwide boycott of Jewish businesses on April 1. Laws soon restricted Jewish students and professionals. The Nuremberg Laws of September 1935 removed Jews from citizenship and prohibited marriage between Jews and people classified as having “German or related blood.” Nazi authorities then forced Jewish business owners to surrender property and livelihoods. The [Museum’s account of prewar anti-Jewish legislation](https://encyclopedia.ushmm.org/content/en/article/anti-jewish-legislation-in-prewar-germany) shows how discrimination was built into law and administration.

## Persecution escalates into mass murder

On November 9 and 10, 1938, Nazi leaders coordinated a nationwide pogrom known as Kristallnacht. More than 1,400 synagogues were burned, thousands of Jewish businesses were vandalized, and about 26,000 Jewish men were imprisoned in concentration camps. The regime’s persecution escalated further during World War II into systematic mass murder. Between 1941 and 1945, Nazi Germany and its collaborators killed Jews through mass shootings, lethal conditions, gas vans, and killing centers. The [Holocaust Memorial Museum’s Holocaust introduction](https://encyclopedia.ushmm.org/content/en/article/introduction-to-the-holocaust) describes this process and establishes the six-million death toll.

Knowing this history helps identify antisemitism when old accusations return in new forms: claims of secret Jewish control, demands that Jews answer collectively for others, or threats against Jewish institutions. Explore the pages linked above for concrete examples, evidence, and practical responses.

## ページ

- [反ユダヤ主義の仕組み：神話、差別、暴力](/resources/antisemitism/expressions-of-antisemitism.md)
- [ホロコースト否定と歪曲：証拠が示すこと](/resources/antisemitism/holocaust-distortion-and-denial.md)
- [反ユダヤ主義とイスラエル：批判が一線を越えるとき](/resources/antisemitism/the-new-antisemitism.md)
- [今日の反ユダヤ主義：事件、思想、証拠](/resources/antisemitism/contemporary-challenges.md)
- [反ユダヤ主義にどう対抗するか：教育、法律、地域社会の取り組み](/resources/antisemitism/combating-antisemitism.md)

## 情報源

- [encyclopedia.ushmm.org](https://encyclopedia.ushmm.org/content/en/article/antisemitism)
- [encyclopedia.ushmm.org](https://encyclopedia.ushmm.org/content/en/article/blood-libel)
- [encyclopedia.ushmm.org](https://encyclopedia.ushmm.org/content/en/article/anti-jewish-legislation-in-prewar-germany)
- [encyclopedia.ushmm.org](https://encyclopedia.ushmm.org/content/en/article/introduction-to-the-holocaust)
- [encyclopedia.ushmm.org](https://encyclopedia.ushmm.org/content/en/article/kristallnacht)