Having taught for the past 30 years in a range of schools across the UK, latterly as a headteacher, I am now in the process of writing up my PhD research at the University of Nottingham.Few relationships in English school leadership are as important as that between the headteacher and the Chair of Governors. This can potentially be an entirely fruitful, high-functioning co-created partnership; alternatively, it can be fractious and inharmonious, potentially catastrophic not just for the school but also for the individuals involved. Literature on the subject is limited and focused more on the rationale for the relationship than on its practice.My research involved case studies of eight relationships of headteachers and Chairs in English secondary schools, in both the state-funded and independent sectors, to examine how such relationships are forged and developed to identify indicators of successful ways of working. I adopted a Relational Theory perspective, specifically developing Leader-Member Exchange Theory (LMX) to focus on a relationship where both parties possess leader and follower identities. I followed a hermeneutic phenomenological methodology due to a desire to investigate the participants’ lived experience of the relationship alongside my own.The paper finds that the less successful relationships are marked by distrust, dysfunction and personal distress; the more successful are often replicated elsewhere with other senior leaders, leading to a more united and purposeful leadership team. The principal finding is that these relationships involve a complex interplay of operational insight and strategic collaboration but this only emerges and evolves through sophisticated and sustained communication within a context of trust and respect. The term ‘critical friend’ therefore does not reflect the high level of support that both parties can give to each other nor the capacity for considerable professional and personal commitment. The paper concludes with the hope that LMX, and Relational Theory in general, can be utilised more extensively in order to highlight the role that positive and healthy relationships can play in improving school leadership and the lives of school leaders. The ambition for the research is for it to be used by both headteachers and Chairs, and their respective associations, to provide guidance and training to assist in the formation and development of these relationships for the good of their schools and their own wellbeing.