Paul Joseph Diamant was born in Vienna to a wealthy Jewish family who owned estates. After WWI, and after he became an ardent Zionist, he turned his estates into a halutzim training center. He was also a leading member of the Revisionist movement in Austria. After the Anschluss, Diamant took an active part in organizing the illegal immigration (1938), and he himself immigrated to Erez Israel. He bought a farm at Moza, near Jerusalem, and begun his genealogical researches. His genealogical interest was stimulated by the fact that many famous Jewish personalities were related to him, including Theodor Herzl and Heinrich Heine. He himself was a direct descendant of Simon Michael, a famous court Jew in the 18th century. He researched enobled Jewish individuals and wrote a book (unpublished) about that subject in order to refute the Semi-Gotha. He collected much material and deposited it with the General Archives for the History of the Jewish People in Jerusalem. He helped to establish the Herzl Museum in Jerusalem. Diamant published many articles and periodicals.