My doctoral thesis concerns the evolution of citizenship and social distinction between the later Antiquity and early Middle Ages in the Iberian peninsula: broadly from the fifth to the early twelfth centuries. Its focus is broad, and it seeks to highlight how social and legal distinctions which characterised the later Roman society survived within the early Middle Ages. Two key elements receive a particular attention in this study: first, the evolution of the Roman concept of dignitas, seen as a major source of social privilege, from Roman-pagan to Christian society; second, the relationship between citizenship and social status in early medieval society. Dealing with the latter point I concentrate on the legal distinction between upper and lower classes in early medieval Spain. I argue that, while in early medieval Iberian society the value of citizenship underwent deep transformations (or even disappeared), the honestiores/{uaniliores distinction, or other related forms of social distinction between upper and lower classes, survived. The criteria of social and legal prestige were not to be found in citizenship, but in other sources of privilege such as wealth, birth, status, and favour of the ruling authority. Privileges and disqualifications continued to characterise members of the higher and lower ranks in both Christian and Islamic societies. The first chapter opens the dissertation with the analysis of a new legal language that reflected the increasing influence of Christian Church in the later Roman idea of citizen. The elaboration of the concept of dignitas both in later Roman legislation and in Christian literature is investigated. The second chapter examines the influence of the later Roman law in defining social status and citizenship, in the Visigothic kingdom. The analysis of the relationship between dignitas and citizenship in Visigothic society is offered. The third considers the concept of `citizenship' in Muslim Spain. It focuses on the social differentiation which characterised Islamic society. Finally the fourth chapter explores the relationship between higher and lower classes in the Christian kingdoms of Asturias and Leon.