The events of September 11th occurred twenty years ago this year. The destruction of the Twin Towers in New York and the attack on the Pentagon represented a key moment in history. While the world had experienced multiple terrorist acts previously, this event exposed the vulnerability of civilian populations in major Western countries to attacks from extremists. On this 20th anniversary of 9/11, it is clearly a time for reflection on such events and for those in the education field to consider what role schools can play in challenging potential attraction to extremist viewpoints. This report aims to answer the following questions: (1) What role can schools play in enabling young people's resistance to joining extremist or violent movements? (2) What role can schools play in supporting young people to challenge ideas perpetrated by extremist or violent movements? and (3) What classroom resources and support do teachers require to address issues of extremism and violent movements? The current study draws on: a literature review of empirical research examining how schools, and their teachers, build resilience to extremism in students in England and prevent them from being drawn into violent groups; a survey of teachers; and in-depth interviews with English and Religious Education teachers and safeguarding leads in schools, and a Prevent officer. The study is not only concerned with violent extremism, but also with 'hateful extremism' (Commission for Countering Extremism, 2019) which includes homophobic, misogynistic and racist (including Islamophobic and anti-Semitic) attitudes and behaviours. Whilst an attraction to violent extremism was not common in schools across the study, almost all the teachers surveyed had encountered 'hateful extremism', in the form of racist views, in the classroom. Such views lay the foundations for violent extremism. [This report was prepared by the Institute of Education's Centre for Teachers and Teaching Research. The research was commissioned by SINCE 9/11.]