Accepted definitions of educational leadership practice typically view it as influence to achieve organisational goals. Such definitions have been widely used over the last 30 years. During that time, the number of educational leadership theories/models has increased and cover the many aspects of educational leadership all of which implicitly or explicitly use the accepted definition. However, the accepted definition is open to critique in a range of important ways and we consider that a more robust definition is required. In this article, we reconceptualise and redefine educational leadership practice as 'legitimate interaction in an educational institution intended to enhance engagement with the institutional primary task'. We analyse the concepts underpinning the key aspects of that definition: the institutional context of educational leadership practice; legitimacy and educational leadership practice; the interactional nature of educational leadership practice; institutionalisation and institutions; the notion of engagement and the necessary conditions of capability, opportunity and motivation; and the institutional primary task.