He was educated at Constance under the renowned teacher Bernard of Constance. He attended the Lenten Synod of Rome, in 1079, at which Berengarius of Tours retracted his errors. Remaining in Italy till 1084 he probably attended the Council of Piacenza, on the proceedings of which he is the main authority.
Once more at Constance, he attended the ordination of bishop Gebhard and was ordained priest himself by the papal legate. In 1086 he went with Bishop Gebhard as counsellors to Herman, contender for the Imperial crown, at the Battle of Bleichfeld. About the same time he entered first the Benedictine Abbey of St Blasien in the Black Forest and then, in 1091, the Abbey of All Saints nearby in Schaffhausen, where he died.
He wrote seventeen surviving tracts which are mostly apologetics for the pope's policy, defences of papal supremacy or vindications of men who advocated or enforced it in Germany. Chief among these are: De prohibendâ sacerdotum incontinentiâ (against married clergy); De damnatione schismaticorum and Apologeticus super excommunicationem Gregorii VII (justifying excommunication of schismatics and of Henry IV, Holy Roman Emperor and his partisans).
Of broader interest is Bernold's chronicle, Chronicon, the latter part of which is a terse record of contemporary events by a knowing and intelligent observer in the extreme Papal camp.
Bernold was the author of Micrologus de ecclesiasticis observationibus (c. 1085), a lengthy commentary on the papal liturgy that became an important medieval liturgical treatise. Thanks to him, the German church was provided with a fairly common sacramentary throughout the Empire. The form of the mass given in Micrologus was established for Hungary, too, about 1100, by order of the local bishops.
- Autenrieth, Johanne (1955). Bernold von Konstanz. In: Neue Deutsche Biographie (NDB) (in German). Berlin: Duncker & Humblot. p. 127. ISBN 3-428-00183-4. Retrieved 26 October 2017.
- Catholic Encyclopedia: Bernold of Constance