In August 1933, Arab, Turkmen, and Kurdish Iraqi soldiers in northern Iraq carried out the massacre of Assyrian families in the village of Simele. This complicated moment underlined the volatility of the region as well as the central government’s difficult relationship with its diverse and underdeveloped periphery. Over the ensuing twelve years until the end of the British occupation and the beginning of large scale oil extraction in northern Iraq, attempts by Baghdad to create a nation-state that included the northern region ran into a number of obstacles, especially regarding many groups that remained outside of the ethno-religious lines of the Iraqi power center. This uneven development and incorporation would lead to a shaky and uncertain foundation for later Iraqi economic and national development after 1945. This paper will examine state policy regarding subaltern groups such as the Shammar Arabs, Yezidis, and Assyrians generated by British colonial authorities and their Iraqi counterparts between 1933 and 1945, the final year of the second British occupation. As the state attempted to modernize as well as define the spatial conceptualization of the nation, it encountered challenges among rural, nomadic, and other groups that remained outside of the urban milieu. Often, these groups would come into conflict with each other, which at times resulted in increasing degrees of state intervention. This paper argues that while the state apparatus made a number of varied attempts to incorporate these groups into the new nation-state, it was largely unsuccessful, leading to an uneven course of modernization into the postwar era. The British occupation after the 1941 Anglo-Iraqi War imposed a further layer on top of the state’s efforts, where British geopolitical interests came before Iraqi national ones. Many times, British officials would observe violence develop as a result of this failure of incorporation as horrified bystanders, while other times attempted to intervene with varying results. This paper utilizes documents compiled by the Baghdad High Commission, showing the interplay between officials in the capital, their concerns and anxieties about the periphery, and ways in which the periphery was able to influence policy. The state used policies such as conscription, border patrols, work camps, and collaboration with perceived local elites in order to reach its goals.