Changes of social order in societies in remote times up to the present time have had a major impact on the use of address systems and their change, as has language contact due to population movements whether forced or unforced. There are several important factors influencing these changes involving processes of (de)grammaticalization and pragmaticalization. Indeed, there is a series of extra-linguistic variables associated with pronominal address including social position, relative authority, group membership, generation, age, sex, kinship, genealogic distance, mood, social context, and language variety. It is precisely these features which turn second person pronouns into social markers. This chapter has a threefold objective: first, to shed some light on the complex architecture of address systems which Romance languages have developed over time out of their shared Latin heritage; second, to familiarize readers with some of the different kinds of address systems conventionalized in Romance; and, finally, to foreground the processes of language change which led to the great variety of systems present in the post-Latin varieties today.