In all legal systems, establishing maternity and paternity has always been of great importance, especially in the context of family law. Roman law regulated paternity based on the following principles: mater semper certa est („the mother is always known”) and pater is est quem nuptiae demonstrant („the father is one to whom the marriage points”). These rules are still present in the Croatian legal system today. This paper examines how these rules shaped the framework used by Croatian law to establish maternity and paternity, as well as how the legal framework has changed to address modern challenges such as surrogacy and medically assisted reproduction. Although Roman law could not foresee these modern methods of childbirth, it established guidelines that remain relevant, particularly concerning the child's right to origin and identity. Croatian legislation, despite adapting to new technological and social circumstances, continues to apply these fundamental principles, although legal maternity, once unquestionable, can now be contested. The paper also discusses how, although reproductive technologies allow infertile couples to achieve parenthood, they still raise new ethical and legal issues. Nevertheless, despite all technological advancements, the ideal framework for childbirth remains rooted in emotional connection and love between spouses, which continues to be the undisputed foundation of family life.