This book critically examines the concepts of teacher knowledge, the effectiveness of teaching, and the relationships between these and the context in which teachers work and live. Providing an original analysis of empirical evidence from the UK Department for International Development's substantial 20-year language teacher education programme in China this study demonstrates how both the understanding and effectiveness of teaching and teacher education are shaped by cultural contexts and traditions. The author points out the difficulties caused when teacher educators fail to realise this. Qing Gu also reveals the importance of identifying variations in teacher knowledge within single cultures and areas of common ground across cultures, articulating the key findings for sustaining and improving the long term effectiveness of teacher education programmes within the contemporary context of internationalisation.