Drawing on the idea of powerful knowledge, this book interrogates the epistemic quality of education in schools, in terms of what students are expected to know, make sense of and be able to do through the curriculum. In doing so the authors acknowledge the significance of transformation processes through which specialized knowledge, developed in subject disciplines, is reshaped and re-presented in educational environments. Moving beyond the narrow knowledge vs skills debate of the 20th century, the authors look at how we might democratise and open up access to 'knowledge of the powerful' for all through the school curriculum. Arising from the work of the Knowledge and Quality across School Subjects and Teacher Education network (KOSS), funded by the Swedish Research Council (2019-22), this book draws on studies conducted in a range of national contexts, including from Finland, France, Germany, Norway, Sweden and the UK, and considers the implications for curriculum innovation at policy, programmatic and classroom level.