The idea of human rights is rightly considered to be one of the very biggest of the big thoughts of the early twenty-first century. The object of this book is to capture a sense of the variety of the platforms within which human rights law is practised today and reflects the dynamic interrelationships that have grown up between these various levels. It also has a critical edge, where the chapters reflect on the way the subject has been handled in the authors sub-field, how it has achieved what has been expected (or has not) or produced unexpected side-effects, with judgments about the efficacy of human rights law (set against the standards of the field itself or some other goals) not being withheld where it is appropriate for these to be made. Written by world-class academics, this Companion will be essential reading for students and scholars of human rights law.