This chapter discusses teachers' professional learning and leadership of, by, and for teachers by considering changes in policy approaches intended to improve educational systems and the rising interest in teachers' practices and leadership. Genuinely enabling teachers to lead their own learning and practice requires the integration of changes in policies and practice drawing on professional knowledge and research evidence. The chapter proposes that teachers' learning and leadership requires enabling teachers to be agents at the center of educational changes rather than the subjects or recipients of externally mandated reforms only. By the 1970s, significant developments in educational research concerning school effectiveness were emerging also. The concept of "Leading from the Middle" is emerging to examine and advocate for educators in districts and schools to lead change in new ways. The idea of embedding professional learning in practice was strengthened by the organization of the National Board for Professional Teaching Standards (NBPTS).