This book examines the simultaneous protection of fundamental rights by various norms and jurisdictional organs, focussing on the multilevel protection of the principle of legality in Criminal Law.Written by accredited specialists in criminal law, constitutional law, international public law, and the philosophy of law, the majority of them ex-Counsels of the Spanish Constitutional Court, it addresses various manifestations of the principle of legality: the requirement of precision, the judicial subjection to law and the prohibition of bis in idem. It does so not only from a theoretical...