This thesis studies the relationships between newcomers employed by the Hudson’s Bay Company at Fort Simpson and the Ts’msyen people who came to live outside the fort from its establishment in Ts’msyen territory in 1834 until the founding of a Christian Ts’msyen village at Metlakatla in 1862. I argue that a mutually intelligible – if not equally understood – world was developed at this site in which the lives of these newcomers and local Ts’msyen people became intertwined and somewhat interdependent. While this world was not characterized by universal conditions of fellowship and trust it did involve shared Ts’msyen-newcomer participation in significant cultural activities, the repurposing or remaking of each other’s customs, and jointly developed practices in which customs from both groups were intermingled. I propose that some of these practices, particularly those of law and marriage, can be considered as culturally hybrid. This study suggests the compromised position of the HBC on the northern Northwest Coast, Ts’msyen cultural disposition, and dynamics of power within and between these groups fostered the development a mutually intelligible world and hybrid Ts’msyen-newcomer practices. Far from any centre of British power, greatly outnumbered by the Ts’msyen, and soon out-armed, the newcomers of Fort Simpson were particularly vulnerable. Ts’msyen people, it is claimed, generally valued innovation and had a long-established system for acquiring ownership of changes brought from outside into their communities. Ts’msyen women had a special role in this process. Moreover, both the Ts’msyen and the newcomers had hierarchically structured societies in which displays of power and authority were important. These local circumstances were fundamental to the formation of the hybrid institutions of marriage and law at Fort Simpson/Laxłgu’alaams and to the other complex social and cultural interactions of the two groups documented here. While this study acknowledges that Ts’msyen and newcomer people had distinct motivations for entering relationships with each other, for sharing and cross-participating in customs of the other, and for developing new joint and hybrid practices, it argues that for both groups power and authority were crucial factors. The distinct circumstances which made a mutually intelligible world possible at Fort Simpson/Laxłgu’alaams came to an end in 1862. The return of smallpox in Ts’msyen territory, the removal of the missionary William Duncan and his followers from Fort Simpson to Metlakatla, and the increasing colonial regulation of Indigenous people brought an end to the brief period of accommodation and collaboration between HBC newcomers and Ts’msyen people.