This dissertation examines microevolutionary changes in the Eastern Adriatic and hinterland during Roman imperialism, evaluating changing patterns of variation among indigenous groups with varying histories of acceptance or defiance to Roman rule. Despite the prevalence of Roman influence, trade, and the accommodating nature of Roman political authority administered through existing local leaders, Eastern Adriatic and hinterland peoples underwent significant cultural transformations. Unlike the Roman-allied Liburnians, Romanization was not a voluntary and amicable process for the resisting Delmatae, Histri, Japodes, and Pannonians. The violent experiences of locals during the late Republican Period and early Roman Empire, including death, enslavement, conscription, and displacement, contrast with the eventual integration of the region by the end of the Roman Empire, when their descendants were Roman citizens. These complex histories make it challenging to understand local identities and the impact of Romanization. Biological distance analyses of dental morphology from Liburnian, Delmatae, Japodes, and Pannonian samples representing 313 individuals dating to the Iron Age (c. 700- 400 BCE), and Roman Period (Roman Republic c. 200- 0 BCE; Roman Empire c. 1- 500 CE), were contextualized with archaeological data and classical research. Results indicated no significant differences within Eastern Adriatic and hinterland populations across the time periods. However, interpretations of the results for Roman Period Liburnians, descendants of Roman allies, suggest differentiation from contemporaneous Italic Romans. Conversely, the descendants of resisting populations were not statistically different from Roman Empire Italics, potentially influenced by their ancestors’ experiences of war affecting subsequent admixture, community formation, and adherence to prevailing norms. Roman laws that managed access to advantageous status identities through marriage and citizenship may also explain the findings that all surveyed local populations demonstrate continuity between ancestors and descendants. The dynamic of being identified as Roman, and yet descending from the people who fought against Rome, is further discussed as a form of biological imperialism, consequentially shaping indigenous ancestral ties within a pan-regional Roman citizenry. While Roman multiculturalism is often considered exemplary of Antique Period diversity, Roman values prioritized diversity when it was advantageous and used pluralism to encourage cultural assimilation and define outsiders.