The indigenous nation of the Lipan Apaches initiated diplomatic interaction with European powers beginning with colonial Spain in the early eighteenth century. In the nineteenth century, Lipan Apaches engaged the sovereign entities of the Republic of Texas, Mexico, and the United States. My thesis examines relations between the Lipan Apaches and external sovereigns from the advent of the Republic of Texas in 1836 to the 1856 massacre of people in Mexico. During this period, the Lipan asserted their own internal polity through democratic organization as well as external diplomatic negotiations with other nations. The thesis focuses on how Lipan Apaches attempted to establish boundaries relative to the Republic of Texas, the United States, and Mexico in an assertion of indigenous sovereignty. The thesis argues that sovereignty in the case of the Lipan Apaches consisted of community cohesion and diplomacy with other nations. This historical study begins with a literature review and then focuses on Lipan Apache external social relations with the Republic of Texas. Next, the thesis discusses autonomous relations with the settler states of Coahuila, Nuevo Leo�n, and Tamaulipas in northeastern Mexico. The final chapter discusses treaty relations between the United States and the Lipan Apaches. In this part, the thesis promotes the idea that this indigenous nation linked itself to the settler state. Later, however, the United States delinked from the Lipan Apache nation and then promulgated a number of massacres against Native peoples including the Apaches. In my conclusion, I analyze the impact of indigenous theoreticians of sovereignty in an effort to determine the significance of this legal concept in understanding intergovernmental relations between Native Americans and the diverse settler states in the mid-nineteenth century.