We present the design, deployment and evaluation of three configurations of an online learning activity for would-be social innovators and activists, with the aim of understanding the factors that are critical to the design of an infrastructure to support such communities of learners. Our research was inspired and motivated by the example of SOLEs (self-organised learning environments) and builds upon the experiences of early connectivist MOOCs (massive open online courses). Our configurations were used to deliver three pilot courses on the topic of Sustainable Development, in partnership with United World Colleges (an organisation of international schools). Our work is distinctive in putting a focus on civic engagement and the autonomy of student learners throughout the course. Our primary design goals were to enable activist empowerment; self-organized learning, and the creation of social bonds to facilitate a lasting and self-sufficient international activist community. We base our analysis on a sample of 114 active learners and 33 mentors; including data from 223 applications, 705 Facebook posts, 48 participant survey responses and a variety of quantitative metrics.