The Curriculum, Evaluation and Management (CEM) Centre has grown in just 25 years to become the largest educational research unit in a UK university. It has influenced schools and teachers in unprecedented numbers and has had a considerable impact on policy and practice both directly and indirectly in the UK and beyond. This article summarises this growth and points to key features of its success. It recounts the philosophical approach of the centre and gives examples of its work to illustrate the way in which it has worked. This includes the development of monitoring systems, the creation of innovative tests, the use of monitoring data in research projects, evaluation and the centre's commitment to evidence-based work. The article does not report findings in the manner of many journal articles. Rather, it describes the growth and key features of a remarkably successful centre. It seeks to justify this claim and to outline the manner in which it has been successful. (Contains 1 figure, 1 table and 1 footnote.)