It is a little known fact that New Zealand was both a British colony and imperial power in the Pacific during the twentieth century. From 1901 to 1965, under the pretext of a civilising mission, New Zealand exercised moral responsibility for the Cook Islands. Beneficent overtones concealed the colony's quest for territory and power, and political rhetoric continues to ignore the deficiencies and injustices of their former rule. As patriotic British subjects, and nominal citizens of New Zealand, the Cook Islanders looked to their colonial rulers for a pathway into the modern world. Contact with administrators, teachers, traders and missionaries instilled a sense of kinship, and mass movement to New Zealand in the post-war era is a recognised consequence of these historic ties. This migration is generally regarded as an immediate response to employment opportunities at that time.This thesis explores the social realities of New Zealand's colonial relationship with the Cook Islands. It draws primarily on the records of the Island Territories Department to address issues of citizenship and status in relation to the Cook Islands' people. Efforts to control population movement and monitor Cook Islanders in New Zealand bring the powers of New Zealand officials under scrutiny. This approach uncovers the nature of New Zealand rule, and exposes the political and socioeconomic forces that fostered Island discontent. Focusing on the dissemination of knowledge, this history traces the Islanders evolving awareness of the wider world from the time of European contact. The writings of early commentators, newspaper accounts of social exchanges, and the stories of early migrant women reveal the range of interactions influencing new patterns of movement and early permanent migration. Political, familial and cultural associations between New Zealand and Cook Island Māori are highlighted as influential in promoting a sense of belonging to Aotearoa New Zealand, and encouraging and facilitating movement to and from the Islands. This thesis demonstrates the potentially liberating effect of war on the Cook Islands psyche. World War One soldiers returned to the Islands with heightened social and political aspirations, but were forced to resubmit to white hegemony. During World War Two, young Island women recruited for domestic service in New Zealand unwittingly challenged colonial power relationships by choosing permanent residence. Their newly-acquired status confirmed the reality that Cook Islanders could only attain the full rights and privileges of New Zealand citizenship by making a new home in the metropole. This thesis contributes to the history of female immigrants (migrants) and their settlement in New Zealand, and reveals single women as the original promoters of chain migration from the Cook Islands in the twentieth century. It uncovers a sound knowledge base informing Cook Islanders of potential lifestyle opportunities in New Zealand, one formed well before 1950. It thereby confirms that post-war migration to the metropole was a more measured and premeditated response than previously thought.