This paper considers the professional development of a group of 75 primary and secondary teachers in Melbourne, Victoria, who had been charged with the responsibility of leading the professional learning of their colleagues in their schools. To support these leaders of professional learning in their roles, the Victorian state government's Department of Education and Early Childhood Development contracted members of the Pedagogy and Professional Learning Research Group at Monash University to develop and implement an appropriate Professional Learning program. The Leading Professional Learning (LPL) program ran for seven months and consisted of a series of four face-to-face workshops that were sustained through the formation of peer networks. Each participant in the program was responsible for designing and implementing a school-specific professional learning project appropriate to their school setting. At the final workshop in the LPL program, participants reflected on and recorded their learning through the formalised process of case writing. Their cases were published in a book of Cases of Professional Dilemmas and form the basis of the data-sets that have been used to research participants' learning about leading the professional learning of their colleagues. As a consequence, this paper offers interesting insights into the journey of these educators of teachers as they have developed deeper understandings of what it means to be a teacher educator.