The marital property regimes, inheritance practices, and kinship structures of Renaissance Italy and early modern Portugal were at opposite ends of a spectrum. In Italy, the legitimacy of marriage was defined as the outcome of dowry exchange governed by exclusio propter dotem, thus conceptually linked to the disinheritance of daughters and wives. In Portugal, where the Roman principle of equal inheritance was never abolished, domestic unions qualified as marriages insofar as joint ownership was established. Kinship structures were rigidly agnatic in Italy, but cognatic, even residually matrilineal, in Portugal. An investigation of notarial records from Lisbon, Venice, and Florence shows how women's capacity for full legal agency as property owners in both societies differed. Female legal agency, however, whether measured by women's capacity to engage in property transactions independently of their marital status (Portugal), or as the manipulation of limited legal resources, even resistance against a system of dispossession (Italy), always unfolded within the context of larger agendas that were beyond women's control, such as the processes of state formation in medieval Italy and empire-building in Portugal.