This presentation is divided into two parts. The first part traces the journey of ISSPP over the twenty-plus years of its existence. The second part summarises the articles in this special issue to find whether there is a common approach and understanding around successes and successful leadership. We choose to characterise the work of the ISSPP as an expedition, not a journey. The reason for this is that the starting point was a genuine interest in understanding successful school leadership—both from the principals’ and teachers’ perspectives and from external measurements of student results, or, where these were unavailable, reputation. At the early meetings of the initial group of 8 countries, we were not primarily looking for theories or models to guide our work. Instead, the discussion centered on what kind of empirical knowledge was missing about successful principalship. What is evident after reading and summarising the country reports is that all the authors try to find a conceptual model in which they analyse empirical material that has been collected with the ISSPP protocols. The models differ, and the output side varies between focusing only on student outcome to having a dual output side with student success and school success. Inside all the models, central, intermediate, or essential factors vary when explaining why the leadership creates successful schools or students. The way successful school principalship is explained is also interesting. There seems to be a clear connection to context and culture. In many articles, values and norms are central to the analysis, and in some cases, the link to the principals’ socio-emotional skills as a prerequisite for success is emphasised. After 20 years of conversation, it is clear that context and ideal differ both within and among the participating countries (Ärlestig, Day &Johansson, 2016). Our common work has helped us see the nuances and complexity of successful principalship and how principals contribute to school success. We have discussed concepts and methods, differences in academic traditions, and an understanding of research.

Ärlestig, H., Day, C. and Johansson, O. (Eds.) (2016), A decade of research on school principals: cases from 24 countries. Dordrecht: Springer. Day, C. and Leithwood, K. (Eds.) (2007), Successful principal leadership in times of change: an international perspective. Dordrecht: Springer. Johansson, O and Ärlestig, H. (in press), Democratic Governing and the Power of Intervening Spaces as prerequist for Student Learning in ”A Journey of Organizational Theory and School Improvement: The Legacy of Karen Seashore Louis. Special issue of the Journal of Educational Administration, to be published in 2022. Leithwood, K. and Riehl, C. (2003), What We Know about Successful School Leadership. Nottingham: National College for School Leadership. Leithwood, K. and Riehl, C. (2005), What do we already know about successful school leadership? In W. Firestone & C. Riehl Eds.), A new agenda: Directions for research on educational leadership (PP. 22-47. New York: Teachers College Press. Leithwood, K. (2021), A Review of Evidence about Equitable School Leadership. Education sciences, Vol. 11 No 8, article 377, 49p. Höög, J., O. Johansson, and A. Olofsson. 2011. “Swedish Successful Schools Revisited.” In How School Principals Sustain Success over Time, edited by L. Moos, O. Johanssson, and C. Day, pp. 73–89. Dortrecht: Springer.