This book offers a policy analysis of the emergence of the General Data Protection Regulation (GDPR) through the lens of John Kingdon’s Multiple Streams Framework. Drawing on 32 expert interviews with key stakeholders—including EU institution representatives (such as trilogue negotiators), member states, industry leaders, NGOs, and journalists—the author provides a deep dive into the decision-making process behind the regulation. Additionally, the study examines 462 position papers from the EU Commission’s consultation phases (2009–2011) to uncover the factors that shaped the adoption of the GDPR. At its core, this work explores the ‘window of opportunity’ that enabled the regulation's adoption.