Beginning with the informal establishment of Jewish Orthodoxy by a Hungarian rabbi in the early nineteenth century, this book traces the history and legacy of Jewish Hungarian Orthodoxy over the course of the last 200 years. To date, no single book has provided a comprehensive overview of the history of Hungarian Orthodoxy, a singularly zealous, fundamental, and separatist faction within Jewish circles. This book describes and explains the impact of this strand of Jewish Orthodoxy – developed in Hungary in the second half of the nineteenth century – across the Jewish world. The author traces the development of Hungarian Orthodoxy in the “new” Jewish territories created in the wake of Hungary’s dismantlement following its defeat in World War I. The book also focuses on Hungarian Orthodoxy in the two spheres where it continued to develop after the Holocaust, namely Israel and the United States. The book concludes with a review of Hungarian Orthodoxy’s legacy in contemporary communities worldwide, most of which are known for their radical anti-Zionist and anti-modernistic strands. The book will prove vital reading for students and academics interested in religious fundamentalism, Hungarian history, and Jewish studies generally.