Recent changes in school leadership emphasise the principal’s pedagogical role in fostering quality learning of students and teachers while retaining the role of manager. New understandings recognise that principals must share leadership with teachers and move from a teaching to learning approach. This paper addresses three areas, each showing the relationship between expectations, preparation and practice: (a) how the roles of pedagogic leader and manager complement each other in making effective instructional improvement, as well as the relevant impacts on the different leadership models (Burns 1978; Fullan & Hargraves, 2003; Gardner, 2000; Godard, 2003; Hopkins, 2001) (b) the results of a mixed quantitative/qualitative study in Slovenia indicating factors for and impacts on leadership that contributed to instructional improvement, how the principals first recognised the incentives and tendencies towards asserting the ‘from teaching to learning’ approach, how they assumed the role of change agent, and which factors (legislation, initial education, training programmes, other forms of professional development, school environment, and others) impacted them in this respect, what competencies they already possessed, and which ones still needed to be developed (c) emerging international perspectives of core competencies for leaders in the 21st century, whether for principals or teachers. The paper indicates a global “teaching to learning” emphasis, leadership for instructional improvement, and a shift in leadership competencies.