The concept of vulnerability has not been unequivocally interpreted either in regional or in universal international legal instruments. This book analyses the work of the EU and the Council of Europe in ascertaining a clear framework or a set of criteria suitable to determine those who should be considered vulnerable and disadvantaged. It also explores the measures required to protect their human rights. Key questions can be answered by analysing the different methods used to determine the levels of protection offered by the two European systems. These questions include whether the Convention and the case law of the Strasbourg Court, the monitoring mechanisms of the Council of Europe, EU law and the case law of the European Court of Justice enhance the protection of vulnerable groups and expand the protection of their rights, or, alternatively, whether they are mainly used to fill in relatively minor gaps or occasional lapses in national rights guarantees. The analysis also shows the extent to which these two European systems provide analogous, or indeed divergent, standards and how any such divergence might be problematic in light of the EU accession to the European Convention on Human Rights.