This book analyses the victory of Gabriel Boric in Chile during the presidential elections of December 2021. He brought the radical left into power, after three decades of centre-left and right-wing governments. In order to explain this abrupt political mutation in the country, the book explores a series of fast and deep social and cultural transformations experienced in the country in the last decades. In addition, the book considers the main features of the new Boric government both in terms of goals as well as performance in his first year in office in several key areas of policymaking. The triumph of the radical left in Chile poses several questions regarding the ability of the Boric administration to guarantee political and economic stability in the country. Among the greatest challenges the Boric government will have to face in the coming years are the reduction of inflation, the reactivation of the economy, the regulation of illegal immigration, and the improvement of public security among the population. This book constitutes the first major academic attempt in the English language to provide a broad analysis of the Boric government in Chile and the changes the country will experience in the years ahead. The book will be of interest to students, scholars and practitioners who are interested in the evolution of the Latin American left in general, and the Chilean left in particular. The book has been conceived from a multidisciplinary perspective, including insights coming from history, sociology, political science, economics, institutional law, and development studies.