Genealogical Family Historians conduct research in order to reconstruct genealogical families, through the application of a rigorous methodology: weighing the evidence for placing each individual in a family group, linking family groups of the past and making contact with kin of the present. Genealogical Family Historians trace the movements and migrations of identified individuals and family groups; and study the local, national and international social settings of lives lived in families and households in different times and places, over many generations. A large worldwide Community of Practice with many constituent groups, including the New Zealand Society of Genealogists Incorporated, has formed itself around this research activity. In this transdisciplinary study focused on social learning, I have explored and analysed the domain, the practice and the community of Genealogical Family Historians researching in and from Aotearoa-New Zealand during the past 50 years. Genealogical Family Historians meet formally and informally, in small groups or at large conferences to pursue their self-directed learning. The collaborative practice includes publishing and teaching; and the locating, preserving and indexing of records. Many conduct research and communicate with others in the new world of cyberspace. My overarching research question has been: where is the future place for this scholarly discourse? My approach to this study is transdisciplinary: my point-of-view is above and across departments and disciplines. The ethos and vision of transdisciplinarity is attained only through existing disciplines, and transdisciplinary research has the potential to contribute to those disciplines, as I demonstrate in this thesis. The transdisciplinary scholarly discourse of Genealogical Family History owes much to the disciplines of history, geography and sociology; and draws on biology, law, religious studies, linguistics, demography, computer science and information technology. I have also drawn on understandings from my own prior and concurrent disciplinary knowledge and experience for this study. Other Genealogical Family Historians bring different disciplinary understandings to the discourse that is Genealogical Family History. My positionality is that of an insider, an involved member of the Community of Practice for many years. In this study, I have allowed my key informants to speak with their own voices; and I have sought illustration and evidence from documentation and observation in the wider Genealogical Family History Community, past and present. I have used enhanced reflection on my own practice in my analysis and in case studies. This study demonstrates how the Community of Practice has played an important role in developing a transdisciplinary mode of inquiry and suggests that there are some generic features of the field and practice of Genealogical Family History that form the substance of a transdisciplinary discourse ready to take its place in academia.