This qualitative case study explores how secondary school teachers innovate in the face of complex simultaneous and ongoing mandated changes and in particular, how they innovate with ICTs. The study argues that by understanding the whole-school context, the integration of ICTs can be better understood. The research setting is a complex independent, monastic secondary school in South Africa. Rather than select exemplary projects which are the usual focus of ICT research, the school was chosen for its combination of highly developed ICT infrastructure, but relative lack of exemplary achievement with ICTs. Using Sherry and Gibson’s (2005) terminology – convergence, mutuality and extensiveness – derived from their sustainability research, this study investigates the interplay of contextual factors that affects teachers’ ability to innovate in their practice, focussing on process innovation and arguing from a complexity and innovation theory point of view. Contextual factors were identified broadly as organisational factors, collegial and professional relationship factors, and ICT factors. Although all teachers were willing to innovate in practice, particularly in response to radical mandated curricular change and an inclusive philosophy, it was found that contextual factors have differing effects on their individual ability to innovate. The study identifies patterns in which not only positive factors converge, but negative factors (termed disconvergent factors) also converge. Collegial and professional relationship factors affect the diffusion or extension of innovation. These are limited by a lack or under-exploitation of lateral communication means. The study concludes that the effects of context are unique to each individual teacher and that their professional learning trajectory needs to be scaffolded and personalised. Both ICT-based and collaborative opportunities should be provided in support of a professional learning community to address the need to diffuse innovation laterally and to enable sharing that will reduce current overload and stress levels.