Family is one of the most “natural” and fluid social constructs of human history and can be easily affected in different ways by social, cultural and religious changes. So why does the pluralisation of ways of forming a family seem to be a new phenomenon, and such a radical one, that to some it appears to be a risk as far as social cohesion is concerned? This question inspired the conference organized by Reset-DoC on “Family regulations in a society with fluid borders”, from which the following papers were drawn. Here, we are trying to understand new ways of conceiving and creating family in our globalized world, as well as the transformations occurred in the definition of citizenship and the legal framework behind new “types” of families.