This book discusses the history and socioeconomic impact of Rerum novarum, the first Catholic social encyclical. Drawn from research presented at the 2016 Heilbronn Symposia on Economics and the Social Sciences, this book resumes the discussion on the origin, dissemination and impact of the Catholic social doctrine which originated in this epoch-making encyclical, arguing that the fundamental concepts of this doctrine have had long-standing influence on the development of the modern social state and social market economy. Beginning with an introductory background on the Rerum novarum, the book moves through chapters focused on the implementation and application of the doctrine throughout its history and the impact it has had on global economics. The book starts with the contributions of precursors and pioneers of the doctrine such as Bishop Wilhelm von Ketteler , proceeds to the reception of Rerum novarum after its implementation, and presents examples of its application. It then moves to the central question of Rerum novarum on the role of land, the taxation of immovable property, and more generally, justice. The book concludes with comments on the wider significance of Rerum novarum and Catholic social doctrine from a sociological and theological perspective. This book will be useful for academic researchers interested in theoretical economic history, political science and history, economic thought, as well as contemporary global and social issues from the perspective of the Christian faith.