This chapter adress the question of knowledge in curricula and introduces theories, concepts and research on how different orientations of the view of knowledge and their respective foundations in different traditions, have consequences for the school's knowledge content and the organisation of teaching in schools. Drawing on research on how the view of knowledge can be related to different curriculum models over time and to how different countries today relate to different forms of knowledge in their curricula, for example knowledge and generic competences (such as 21st century skills), with exmples from case of Sweden. Three dimensions structure the chapter, the institutional, the programmatic and the textual curriculum. Conclusions are drawn concerning how current changes as emerging societal challenges re-configure the content and structures of knowledge in curricula and teacing practices.