Through the research submitted here for the award of a PhD by publications at UEL, I track the significance of my research in the field of early childhood over a period of some 25 years, since I joined the Institute of Education’s Thomas Coram Research Unit at London University in 1985. Alongside the research itself, this thesis takes the form of a critical appraisal of the nine peer reviewed publications (Annex A) selected from a much wider body of work produced during this quarter century (Annex B). This included international academic journal articles, edited academic books, book chapters, official research reports and evaluations commissioned by UK government departments, academic reviews, reports for NGOs and contributions to practitioner publications. In this thesis I aim to demonstrate that the submitted body of research, some of it collaborative, is both original and methodologically rigorous. As well as illustrating its significance to the field and beyond, I argue that it is conceptually coherent in a way which over time has come to characterise my academic output as a whole. These nine publications not only address omissions in the field, but evidence a distinct contribution to the emerging sub-discipline of early childhood policy research within the wider body of early childhood research, attempting an interdisciplinary integration of perspectives. In the present section of this thesis I discuss the origins and conceptual coherence of this body of research, setting the publications within the context of different stages of my research career (Annex C). Each stage built on the learning of the previous one and their interaction has arguably shaped my entire research output and my positioning as a researcher in distinctive ways.