The presence of large numbers of unassimilated Jewish converts to Christianity in southern Italy and southern France in the later Middle Ages led to the creation of a legal anomaly as the neofiti (the New Christians) came to be regarded as a legal entity. At first, there was no special designation for this group, but in the late fifteenth and early sixteenth centuries some official documents from southern Italy mention the term universitas neophitorum. Universitas, in the terminology of medieval legists from the twelfth century onwards, usually designated a group of people having juridical existence, and it was also used to denote “collectivity.” Universitas neophitorum can therefore be understood to refer to a group of converts forming a legal body. The present article supposes a causal link between mass-conversions, the ensuing doubts as to the sincerity of conversion, and the relegation of new converts and their descendants to the status of an unassimilated minority group regarded as a legal entity. Another common factor to be considered is the Angevin dynasty, who ruled Naples from the second half of the thirteenth century until the early fifteenth century as well as Provence in this period of time. Possibly, a tradition of adherence to Roman law played a role in the adoption of a legal concept to be acted upon instead of the exercise of other forms of discrimination against former Jews (such as was the case in the Iberian peninsula).