The history of ideas about Moriori origins, settlement, and culture has yet to be charted across the entire twentieth century. The thesis' primary goal is to begin the documentation of this in detail. It examines the two key strands of thought that have shaped this history of ideas: that Moriori were the remnants of a mainland pre-Maori people, and that they were the descendants of Maori voyagers. These sets of ideas existed simultaneously, which led to an intellectual history shaped by intersecting curves formed through long-ranging debate rather than a single linear progression of thought. Each strand of thought comprised several threads, or ideas about Moriori history that altered over time. The thesis traces this history of ideas about Moriori origins, settlement, and culture through texts, from Alexander Shand's ethnological analysis The Moriori People of the Chatham Islands, published in 1911, to Barry Barclay's 2000 documentary, The Feathers of Peace. It establishes the ideas advanced in key texts on Moriori history, explores the context in which these texts were produced, and suggests a link between shifts in debate and contemporary relations between Maori and Pakeha.