Through a comparative analysis of four long-lived intentional communities in New Zealand, this thesis examines the extent to which each one has sustained, adapted or abandoned its original ideals and aspirations over time. An analysis of in-depth interviews with current and former participants from each community reveals ways that ideological beliefs, organisational processes, and foundation structures have shaped the distinctive cultures that have developed. The relevance of the assertion that long-lived intentional communities share a common purpose and a desire to live beyond mainstream society, and the assumption that longevity and survival can be considered to be the same thing, are challenged. It is concluded that ownership structures for holding land are significant to the longevity of intentional communities, and that the distinctions that once existed between alternative-orientated communities and the larger society that they are situated within have become less clear over time.