The purpose of this study was to explore executive leaders operating in a variety of institutions and their sense meaning of their leadership agency conceptualised as forms of mind. Contextually it seeks to understand the capacity of forms of mind to mature over time into new forms of mind within the broader structure running the meaning-making of Leadership inside their unique organisational context as holding environments. Through a longitudinal analysis of six different organisations, it sets out to understand to what degree individual leaders form of mind relates to their unique organisational holding environment as an expression of their Leadership. Kegan and Lahey (2009) outline how leadership development literature has not focused on the underlying ‘operating system’ of individuals and their meaning making as forms of mind suggesting that effective leadership development needs to be understood within these underlying ‘operating systems’. Furthermore, Laloux (2014) argues that understanding Leadership in organisations is through understanding the stage of development of its leaders. This study bridges the gap between these two places by focusing on examining a gender balance of individual leaders form of mind within the historical-cultural worlds of the underlying operating systems of the holding environments of their organisations. The study reveals that the application of a psychological longitudinal approach to Leadership can provide a practical and meaningful focus in which to understand leaders form of mind in relation to their organisation form of place and how this capacity for developing new cognitions of Leadership inside Constructive Developmental Theory can result in effective leadership development aligned with future organisational needs and complexities. The studys findings can inform future approaches to professional training and development of leaders inside organisations.