Internationalisation and intercultural competence are key ideas in contemporary education and have been much theorised and practised in higher education but have not received the same attention in school contexts. Linked to these ideas is an increasing focus on global citizenship and the development of students’ critical thinking skills and self-realisation. This book is based on a decade of experience of combining all three concepts in the practice of an upper secondary school in Denmark which is linked to 16 schools in 15 countries. The book includes both a description of the project by the teachers who have taken part and an analysis by researchers who have worked with them to deliver the programme.