With the increasing prominence of fundamental rights within the EU it increasingly interferes in the core competence of the Council of Europe. This book traces the EU and the Council of Europe relationship in the field of human rights - marked by mutual interferences and overlap - and explores which factors trigger cooperation or conflict between the two organizations. Investigating the cases of data protection, the fight against terrorism, challenging Roma discrimination, the Memorandum of Understanding and the Fundamental Rights Agency through the lens of an implementation literature and management studies-perspective, this book contends that the biggest threat to interorganizational cooperation is organizational self-interest, despite a shared policy outlook. The book furthers the agenda set by the literature in this field by providing a new theoretical framework and an in-depth empirical study of two main actors in the field of human rights protection in Europe from a political science perspective.