This panel explores how Castilian subjects on both sides of the early Hispanic Atlantic (ca. 1500-1650) interacted with imperial legal structures – by submitting petitions, generating and testifying in formal legal challenges, and even occasionally seeking audiences with the king– in order to negotiate their status in the emerging imperial order. In particular, the panel interacts with three branches of scholarship, which highlight (1) meanings of skin color, race, and difference in the early Spanish empire, (2) the importance of claims to a pure Catholic religious lineage in terms of claiming royal vassalage and subjecthood in the post re-conquest era of the sixteenth-century Castilian world, and (3), explanations for how varied and overlapping systems of imperial law and justice in the Spanish empire provided space for colonial subjects to negotiate the definition of legal categories that determined their rights and privileges within the larger monarchy. The panel seeks to revise and converse with scholarship on race in this period, and broadly, the historical significance of the emergence of categories of difference. The papers of the panel explore how such legal differentiations – between Old Christian, New Christian, negro, indio, mestizo, converso, morisco, and creole, amongst many others—were rarely the product of grand imperial designs, but rather the result of regional and royal attempts to design general solutions to specific problems, tempered by the consistent contestation of individuals who sought to control the rhetoric that surrounded them. Some erstwhile subjects in the Spanish empire sought to identify with heritages that would position them as “Old Christians” (a term particularly salient after the Inquisition’s great purges of the early sixteenth century) and thereby equal - and sometimes superior - to many of their Spanish and Portuguese counterparts. In focusing on how individuals across the early Castilian world employed strategies to claim specific Catholic lineages or develop other legal categories of differentiation or belonging within the empire, the panelists raise important questions about the emergence of a differentiated legal order in this period and the interrelations between religion and “race.” Finally, by reconsidering the existing scholarship’s legal/conceptual framework for analyzing individuals’ search for justice and recognition of privileges within the empire, the panelists engage in a discussion about the impact of methodological and interpretive choices in the study of race and ethnicity, while offering new avenues for understanding the process by which specific groups shaped and negotiated their positions within the imperial order through interactions with legal structures.