German rabbi and historian; born at Dresden July 4, 1870. He was educated at Dresden and at the universities of Breslau (Ph.D. 1894) and Berlin. At Breslau he studied also at the Jewish Theological Seminary and at Berlin at the Lehranstalt für die Wissenschaft des Judenthums. His graduating thesis, at Breslau, was entitled "Versuch einer Technologie und Terminologie der Handwerke in der Mischnah." Rieger was rabbi at Potsdam from 1896 to 1902, when he was called to the rabbinate of the Israelitische Tempelgemeinde at Hamburg. In association with H. Vogelstein he wrote "Geschichte der Juden in Rom" (2 vols., Berlin, 1895-96). He wrote also, besides contributions to various journals, a small pamphlet, entitled "Hillel und Jesus" (Hamburg, 1904).