The issues of antisemitism, war in Palestine and the attitude of the left towards both, are central to contemporary political debate. This book explores the background. Contrary to the Zionist stereotype, before the Second World War the majority of Jews lived in the diaspora, were working-class and were part of a wider struggle alongside their non-Jewish comrades on the left. The book celebrates radical Jewish participation in every corner of the movement in many different countries. Fighting oppression and exploitation took numerous forms, from separatism to solidarity in the shape of left Zionism, Bundism, and revolutionary Marxism. This inspiring radical tradition was ultimately checked by the horror of Auschwitz. However, its lessons must be passed on to modern generations who are once more becoming revolutionaries, resistance fighters and firebrands.