The book is an introduction to the key features of family reunification in EU law. The first part is devoted to family reunification of EU citizens, pursuant to Directive 2004/38/EC. The second section addresses Directive 2003/109/EC on family reunification of Third Country Nationals. The book collects and systematizes excerpts from legal texts and judgments of the Court of Justice of the European Union interpreting them. As such, it is mainly intended for students and other readers willing to deepen their knowledge about this topic. The formatting of the book complies with the most reputed indications on readability for persons with specific learning disabilities.