Although most people know who their parents are, there is a minority that does not. This book deals with the rights of persons, both children and adults, who feel a strong yearning to find out about their biological parents. The identification of biological parents may become important in a wide variety of situations, which run the gamut from adoption to sperm donor anonymity and 'misattributed paternity.' Individual searches across such situations may be motivated by a variety of legal, emotional, and medical reasons. Thanks to bio-medical developments, as well as an increased emphasis on identity rights in international human rights treaties, a broad consensus, that a fundamental right to know one's origins exists, can now be attested. Nonetheless, legal solutions, especially outside the adoption context, have so far largely remained piecemeal. Attention has been drawn primarily to the informational needs of adopted children. As such, manifold legal questions remain regarding the appropriate age for disclosure of information to children, the use of compulsion in DNA testing, not to mention the conflicting rights of a child's need to know vs. parental privacy. In exploring this wide range of legal issues, a thorough comparative study of the relevant law across a number of European jurisdictions has now, for the first time, been made available in English. Foundational Facts, Relative Truths not only provides an in-depth overview of the most recent legal developments in France, Germany, the Netherlands, and Portugal, but it also includes references to some interesting legal solutions found in other jurisdictions. In addition, this study renders similarities and differences visible between the approach of the United Nations' Children's Rights Convention and the ever expanding case law of the European Court on Human Rights. In providing insight into the relevant interpretive tools, this book proposes a set of legal principles that guide the assessment of the current strength of the right to know one's genetic origins. Moving beyond a comprehensive legal theory of the right to know, Foundational Facts, Relative Truths explores the concrete possibilities for a more effective regulation. In this way, it casts a fresh light on the boundaries of State regulation while looking critically at the role parents have in making genetic information accessible to children. (Richard Blauwhoff has been awarded two academic awards for this book Mr. Blauwhoff has received an Erasmus Research Prize in recognition of an exceptional PhD dissertation by a young academic researcher in the field of humanities and social sciences. In addition, he has received the Dutch-German Lawyers Prize, which is awarded biannually to a dissertation or paper on a topic of European law.)