Part I - The Effectiveness of Fundamental Rights in Relations between Private Individuals: The Recurring Debate on the Horizontal Effect of Fundamental Rights. Constitutional Approaches by Marian Ahumada.- The Horizontal Effect of the EU Charter of Fundamental Rights in the Case Law of the Court of Justice by Juan Ignacio Ugartemendia.- The Concept of 'State' for the Purposes of the EU Charter of Fundamental Rights by Carmen Martínez-Capdevila.- A Principle Vanishes and a Right Arises: Paid Annual Leave as a Fundamental Right and its Impact on Liability for Breach of EU Law by Magdalena Nogueira-Guastavino.- Fundamental Rights and Horizontal Direct Effect under the Charter by Nuria Bermejo.- The Horizontal Effect of Social Rights in the Light of the European Social Charter and the European Committee of the Social Rights Case Law by Amaya Úbeda de Torres.- Still on Hijab Bans in the Workplace. À propos de, Joseph H. H. Weiler, 'Je suis Achbita!' by Pedro Cruz Villalón.- Part II - Human Rights and the Rule of Law: Populism and Human Rights. From Disenchantment to Democratic Riposte by Laurence Burgorgue-Larsen.- Rule of Law and Judicial Independence in the Light of CJEU and ECtHR Case- law by Paz Andrés-Sáenz de Santa María.- Judicial Protection against Austerity Measures in the EU by Manuel López-Escudero.- The Overlap between the Principles of Effectiveness and Effective Judicial Protection in EU Law by Fernando Pastor-Merchante.- Part III - The National Margin of Appreciation in Luxembourg and Strasbourg: The Margin of Appreciation in the Case Law of the Court of Justice: Proportionality and Levels of Fundamental Rights Protection by José A. Gutiérrez-Fons.- International Deference, the Vague National Margin of Appreciation and Procedural Review by Javier García-Roca.- The National Margin of Appreciation in the Reform of the Strasbourg System by Cristina Izquierdo-Sans.- A Silent Revolution. Property and Free Enterprise Before the Spanish Constitutional Court by José María Rodríguez de Santiago and Luis Arroyo-Jiménez.