The peace protests which captured public attention in the years since 1945 took place in response to immediate dangers, but they were, nevertheless, linked to a much longer history of peace campaigning. Some of the organizations now active in opposing war and war preparations date from earlier in this century. Some go back very much further: the Quakers, for example, arose in the seventeenth century. Moreover, recent campaigners not only respond to contemporary concerns and arguments but draw also on a much longer tradition of thinking about the problems of war and peace. There are many continuities between past and present peace action, and to gain a full understanding of the present we need to begin by looking very briefly at the history of thought and action relating to peace before the Second World War.