In the current context, effectively including children and young people with additional needs is a challenge for school staff. Conflicting demands placed on teachers, support staff and those who lead them often derail strategic planning for the successful inclusion of all learners. School leaders have to work with complexity and 'mess', whilst containing the often powerful and distressing feelings of children, parents/carers and the staff who care for them. Supporting head teachers to take up their role within complex systems, in ways that promote their on-going learning and development, is vital. Critical are the ways in which their own experiences and feelings can be held to aid thinking. This article outlines some of the constraints currently experienced by head-teachers in England, as well as one potential approach to containment: the provision of relational supervision. The experience of relational supervision, for both supervisee and supervisor, is explored through a case study and some suggestions for future developments offered.