Online communities (OCs) such as Wikipedia have the potential to transform our global society and economy. Building and sustaining OCs, however, appears to be rather complex. Indeed, most OCs fail early on. The extant OC literature cannot fully explain this phenomenon. This thesis is thus motivated by the increasing importance of OCs and the unsolved complexities regarding building and sustaining them. In particular, it aims to answer the research question of how nascent OCs evolve and what the influences are on this evolution. To this end, it examines a longitudinal 34-months long case study of AshokaHub, a nascent global OC of social entrepreneurs, combining interview data with qualitative and quantitative data from the AshokaHub platform. Despite favourable conditions at AshokaHub’s launch and a re-launch with new functionality and curation strategies, user contributions remained limited. Drawing on the OC and social entrepreneurship literatures as well as the theories of affordances, technological frames of reference and groupware adoption, this thesis develops a multi-level model to address the research question. This model theorizes the evolution of nascent OCs and the influence of context and materiality on this evolution. It highlights that OC evolution happens as users across different social worlds within the OC continuously adopt and change their ways of using it. It also highlights that, on an individual user level, this OC evolution happens in a recursive process of framing, affordance perception and affordance actualisation that influences and is influenced by the material characteristics of the OC’s technological platform and is shaped by the OC’s context. This thesis thus contributes to the OC literature by providing insight into how nascent OCs evolve and what influences this evolution. In addition, it contributes to affordance theory by introducing the concept of a collaborative OC affordances. This concept aims to explain how collaborative affordances emerge and evolve on OCs given the generative nature of their underlying technological platforms. These findings have managerial implications as well. Good practices are identified that can support the successful start of an OC. This is complemented with a discussion on how to be situationally aware of the unpredictable evolution of an OC after its start.