This study, with its approach rooted in EU law and its clear focus on conceptual underpinnings, grapples with one of the most challenging questions facing constitutional lawyers today, namely the rule of law. Drawing on the expertise of leading scholars and judges at the forefront of the question, it takes a dual approach. It opens by setting out the foundations of the rule of law, including legal certainty, democratic principles and judicial independence. It goes on to explore the protections that can be relied upon, from policy developments, to human rights sanctions, and infringement actions. This is a rapidly developing question in EU constitutional law, so this masterful collection will be welcomed by both scholars and policy-makers in the field.