For ten years, the GDPR has shaped the protection of privacy in Europe and beyond. As a globally recognised benchmark for data protection, it has set enduring standards. Marking its 10th anniversary, this English-language casebook brings together around 50 renowned authors from industry, legal practice, public authorities, the judiciary, and academia. Through selected landmark decisions and regulatory guidelines, the contributors analyse the key developments shaping European data law. The chapters offer concise, authoritative guidance on the core principles and their practical application. The volume will be presented at the 2nd EuDIR Symposium, held in cooperation with the Cologne Research Centre for Media Law on 20 May 2026 at TH Cologne.