This chapter examines how the previously conducted research into language teacher autonomy informs our current knowledge about teacher development. In addition to methodological characteristics of studies, the focus is on how quantitative studies reveal teacher autonomy levels in multiple contexts and on the developmental activities and areas of autonomy that were induced in the qualitative studies. More specifically the aim is to reflect on the accumulated knowledge iof language teacher autonomy over the past decade. In this chapter, we conducted a systematic and comprehensive review.