If the quality of an education system can never exceed the quality of its teachers, then countries need to do all they can to build a high-quality teaching force. Teaching Excellence through Professional Learning and Policy Reform: Lessons from around the World, the background report to the sixth International Summit on the Teaching Profession, describes the knowledge, skills and character qualities common to the most effective teachers. It examines the education policies and practices that help teachers to acquire these tools, including through induction and mentoring programmes, ongoing professional development activities, student assessments, and collaboration with colleagues. The publication also discusses the importance of involving all stakeholders – especially teachers – in the process of education reform.