BERTOLDO of REICHENAU. — Chronicler, m., according to the testimony of Bernoldo of Constance, on 12 March 1088, at an advanced age. A disciple of Hermannus Contractus, he was a monk of the abbey of Reichenau, on Lake Constance. He continued the chronicle of Hermannus from 1054, the year in which it had been left unfinished, up to 1080, prefacing his work with a detailed biography of his master. The *Bertholdi Annales*, not free from errors, no longer exist in the original manuscript, but only in copies of it, and have been published in *MGH, Scriptores*, V, v, pp. 264-326 and in *PL* 147, 339-442.
BIBL.: J. Richter, *Die Chroniken Bertholds und Bernolds*, Colonia 1862; A. Potthast, *Bibliotheca historica Medii Aevi*, I, 2nd ed., Berlin 1896, p. 158; A. Fliehe, *La reforme grégorienne*, II, Louvain 1926, pp. 39-43.