Possibly the most influential jurisprudent of the twentieth century HANS KELSEN 1881 1973 was legal adviser to Austria s last emperor and its first republican government the founder and permanent advisor of the Supreme Constitutional Court of Austria and the author of Austria s Constitution which was enacted in 1920 abolished during the Anschluss and restored in 1945 He was the author of more than forty books on law and legal philosophy Active as a teacher in Europe and the United States he was Dean of the Law Faculty of the University of Vienna and taught at the universities of Cologne and Prague the Institute of International Studies in Geneva Harvard Wellesley the University of California at Berkeley and the Naval War College