This book presents a comparison of the development of legitimate expectations and proportionality in European and English law against the different traditions of administrative law. While these two principles are well established in European law,only in recent years have the English courts years sought to integrate them into the common law and have experienced various difficulties in doing so. This book seeks to understand the motivation behind this development, explain why the English courts have been troubled by the principles and suggest how such difficulties can be resolved. It will be of interest to all administrative lawyers, both in practice and in academe. It will also be of interest to EU lawyers, particularly those interested in EU public law.