HALLER, JOHANNES. - Protestant historian, b. 16 October 1865 at Keinis (Estonia), d. 17 January 1948 at Tubinga. Having completed his university studies at Dorpat, Berlin, and Heidelberg, he was in Rome from 1892 to 1897 at the Prussian Historical Institute. Professor of auxiliary sciences of history at Marburg (1902-1904), he subsequently taught history at Giessen (until 1913) and at Tubinga.
A profound scholar of the history of the Middle Ages and the modern age, he gained renown through the publication of sources on the Council of Basel (Concilium basilense, Studien und Quellen zur Geschichte des Konzils von Basel, 5 vols., Basel 1896-1904). His fundamental work, however, is the history of the papacy as idea and reality through the centuries, reaching down to the time of Innocent III (Das Papsttum. Idee und Wirklichkeit), the first volume of which appeared at Stuttgart in 1934, followed by the two parts of the second volume in 1938 and 1939. Author of valuable syntheses (Die Epochen der deutschen Geschichte, Stuttgart 1923; Tausend Jahre deutsch-französische Beziehungen, ibid. 1930), among his last studies may be recalled: Piero da Monte, ein Gelehrter und päpstlicher Beamter des 15. Jahrhunderts (Rome 1941), and Pseudofidors erstes Auftreten im deutschen
Investiturstreit (in Studi gregoriani, II, Rome 1947, pp. 91-101).