This book studies the implications for third-country nationals of the adoption of the Long-term Residence Directive. This Directive has the potential to become a subsidiary form of EU citizenship which escapes direct control by Member States. Hence, this Directive brings the prospect of transforming Member States’ control over the relationship between territory and population. In order to arrive at this conclusion, the book looks at its content and at the way in which Member States have implemented some of its most controversial articles. It then explores how the Court of Justice could interpret those articles, taking into account its previous jurisprudence on Turkish workers and EU citizens and calling into question the compliance of several national provisions with EU law.