Leading is not the same as teaching, and middle leaders in schools require different capabilities to those of classroom teachers. This article explores the ways in which these capabilities are acquired by middle leaders in the independent sector during the early stages of their appointment as they progress through a transitional period. It draws on two previous strands of research -- the part that experience plays in informing the emergent leader's development and the acquisition of capabilities over time -- from which a theoretical perspective is used in analysing data derived from a series of interviews with 20 middle leaders as part of a case study in an independent school in the North West of England. The findings from the study are combined with these two strands to demonstrate the central role that experience plays in the leader's capability set and how, during the early period of appointment to a leadership position, the reflection on experience can significantly ease the transitional period. It is recommended that aspiring middle leaders should actively seek out experience, and that senior leaders should proactively make experiential opportunities available. It is also recommended that such action can be applied to other step changes in the teacher leader's career.