When dealing with mixed marriages, it is essential to replace the notions that seem most “obvious”, such as groups of origin, identities... in their historical and political context. After a glance at her personal involvement in this research – initially aimed at exposing the power struggle in conjugal relationships – the author offers a historical perspective on how the meanings of the terms 'mixed' and 'mixity' have been developed in connection with gender, religion, and nationality. She ends with a rapid overview of some French studies on mixed couples, stressing the changes that have taken place since the 1950s.