Within the third sector, scarce resources make it difficult for social enterprises to survive financially, become more innovative and entrepreneurial, and generally grow and develop to scale. Although there is no agreement on the definition, the extant literature tends to frame social enterprise as critical for addressing challenging social problems. Social enterprise involves some degree of profit-making, while maintaining a strong focus on social mission. The latest literature points to social enterprise as an example of a hybrid organisational form that has the potential to act as a solution to complex social problems. However, the literature also highlights the considerable tensions inherent in hybridity, as well as the substantive mission-drift that inevitably occurs. The current body of knowledge does not describe how social enterprise growth and development occurs, nor does it adequately illustrate how social enterprise hybrids can continue to meet their important social missions while generating sufficient operating income to sustain themselves. Additionally, there is a dominant view that non-profit social enterprises may face difficulties in surviving as hybrids due to the risk of mission-drift. An in-depth study of non-profit social enterprises that had already reached scale was undertaken to address this. By doing so, a contribution was made to the development of the social entrepreneurship and social enterprise fields. The theory on social enterprise ideal-types was deepened. In addition, this study provides a framework for social enterprise growth and development within this organising context. Strategy-as-practice (SaP) core concepts as influencers within an entrepreneurship-as-practice (EaP) theoretical framework, contained by a social practice theory theoretical lens. The result was a focus on daily business management and strategic development practices. Additionally, contextualisation – as the link between the micro-context in each organisation and macro environment – was studied as the context for this growth and development. / Thesis (DPhil)--University of Pretoria, 2020. / Gordon Institute of Business Science (GIBS) / DPhil / Unrestricted