A key contributor to the 1948 New Education Fellowship "The Teacher and World Peace" submission to UNESCO, Alex Bloom is one of the most remarkable pioneers of radical democratic education of the twentieth century. In many important respects, Bloom's internationally renowned work from 1945-55 at St George-in-the-East Secondary Modern School in the East End of London can be seen as an iconic example of education for peace. Wounded in World War I, a teacher and then head teacher between the two World Wars and during World War II, this article explores key aspects of his commitment to a form of democratic education that was both a response to two great conflagrations of the twentieth century and a contribution to the possibility of less destructive ways of living and learning together in the future.