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Onno Klopp

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Historian, b. on 9 October, 1822, at Leer (East Friesland); d. at Vienna, 9 August 1903. After finishing his studies at the gymnasiums of Leer and Emden, he devoted himself, from 1841 to 1845 to the study of philology and theology at Bonn, Berlin, and Göttingen, receiving the degree of Doctor of Philosophy at Jena in 1845. He was then appointed to teach at the gymnasium in Osnabrück, retaining this post until 1858. Meanwhile he devoted himself diligently to the composition of works on pedagogy, publishing first, "Die Reform der Gymnasien in betreff des Sprachunterrichts" (Leipzig, 1848), in which he pleaded for modern languages, maintaining that lingual studies should begin with living, not dead languages. He also wrote some books for the young founded on German legends and history, such as "Gudrun. Der deuchen Jugend erzählt" (Leipzig, 1850); "Geschichten, charaktersstische Züge und Sagen der deutschen Volkstämme aus der Zeit der Völkerwanderung bis zum Vertrag von Verdun" (2 parts, Leipzig, 1851); "Leben und Taten des Admirals de Ruiter" (Hanover, 1852, 1858, 1905); "Geschichte und Charakterzüge der deutschen Kaiserzeit von 843-1125" (Leipzig, 1852, 1905); "Deutsche Geschichtsbibliothek oder Darstellungen aus der Weltgeschichte für Leser aller Stände" (4 vols. Hanover, 1853-56), with the collaboration of various scholars. The Revolution of 1848 incited him to scientific historical researches, by means of which he tried to explain the existing phenomena by tracing the evolution of historic conditions. His pamphlet entitled "Die Grundrechte des deutschen Volkes" (Osnabrück, 1849) bears evidence of this.

His most important work at this time was, his "Geschichte von Ostfriesland" (3 vols., Hanover, 1854-58). The East Friesland Estates furnished him with funds for the publication of this work, but, on the appearance of the third volume, they could not refrain from calling attention to the fact that it showed a hostile attitude towards King Frederick II of Prussia. Klopp considered himself unjustly blamed, and declined to receive the subvention for this volume. His action caused a great sensation, and King George V of Hanover, who had awarded him a gold medal for the second volume, paid the subvention from his private purse and offered to take him into his service. However, no suitable position was vacant at the time, and Klopp retired from public office to devote himself entirely to his historical studies. At the same time he took a great interest in the problems of the day, and soon became one of the most important leaders of the greater German party in Northern Germany, the Austrian Ambassador in Hanover aiding him in his efforts. In 1865 the King of Hanover created a commission for the care of the state archives and made Klopp reporter with the title of archivist. He went over the state archives, instituting important innovations in the manner of preserving them, which have been also adopted in the Prussian archives. During the war of 1866 he spent his time at headquarters near the king, in whose services he made two dangerous journeys to Frankfurt and Bavaria. After the capitulation of Langensalza he went to Vienna, where he drew up a petition for peace for his sovereign to King William of Prussia. He now settled permanently in Vienna, and to the end remained a faithful subject as well as a devoted admirer of George of Hanover, as shown by his book, "King George V. Every inch a King" (Hanover, 1878). In 1873 he became a convert to Catholicism. In consequence of his historical investigations he had been for years convinced of the truth of the Catholic Church, giving expression to this view in his three works, "Studien über Katholizimus, Protestantismus und Gewissensfreiheit" (Schaffhausen, 1857), "Wird Deutschland wieder Katholisch werden?" (Schaffhausen, 1859), and "Der evangelische Oberkirehenrat in Berlin und das Konzil" (Freiburg, 1869).

His numerous historical writings can be divided into three groups. The first deal with German and Prussian history, the most important works being the following: "Das Restitutionsedikt im nordwestlichen Deutschland" (Göttingen, 1860); "Der Konig Friedrich II. von Preussen und die deutsche Nation" (Schaffhausen, 1860-7); "Tilly im dreissigjährigen Kriege" (2 vols., Stuttgart, 1861), enlarged edition under the title: "Der dreissigjährigen Krieg bis zum Tode Gustav Adolfs" (Paderborn, 1891); "Die preussische Politik des Friederieianismus nach Friedrich II." (Schaffhausen, 1867); "Rückblick auf die preussische Annexion des Konigreichs Hannover" (Munich, 1868). The work on Tilly found great favour among Catholics, and the Emperor of Austria, as well as the Kings of Bavaria, Belgium, and Hanover, almost simultaneously sent him their gold medals for science and art. On the other hand, his works on Frederich II evoked sharp criticism from Pressian circles, and brought forth many replies, most of which he answered convincingly, as in his "Kleindeutsche Geschichtsbaumeister" (Freiburg, 1863).

The second group of writings are on the philosopher Leibniz. In 1861 Klopp made a proposition to the King of Hanover to publish Leibniz's works. For this purpose he thoroughly examined his entire literary remains, and subsequently published: "Die Werke von Leibniz gemass seinem handschriftlichen Nachlass in der Bibliothek zu Hannover. Erste Reihe: Historischpolitische und staatswissenschaftliche Schriften" (11 vols., Hanover, 1864-84). The completion of this work, however, was made impossible, as Bismarck forbade him the use of the Hanoverian library. The French Academy of Sciences in a letter to Klopp lamented this interdiction on behalf of science. Later Klopp gave himself up to the exhaustive study of the history of the Stuarts. He had taken up this study with great zeal when he was in England in 1859, and in 1870 instituted further investigations of the English archives. The most important work that we have to thank him for on this subject, and one which is perhaps his masterpiece, is: "Der Fall des Hauses Stuart und die Succession des Hauses Hannover im Gross-Britannien und Irland im Zusammenhang der europäischen Angelegenheiten von 1660-1714" (14 vols., Vienna, 1875-88).

The interest he took in the history of Austria, his second home, is shown in his works: "Das Jahr 1683 und der folgende grosse Turkenkrieg bis zum Frieden von Carlowitz, 1699" (Graz, 1882), and "Corrispondenza epistolare tra Leopoldo I imperatore ed il P. Marco d'Aviano Cappucino" (Graz, 1886), which was dedicated to Pope Leo XIII on the jubilee to celebrate his fiftieth year as a priest. We are indebted to Klopp above all for the new lines of historical research which he pointed out to Catholics, his works proving incontrovertibly in defiance of all attacks that the study of original documents based on these lines and carried on with an incorruptible love of truth, will expose the errors of existing history.


Compare the biography written by his son in Biographisches Jahrbuch, VIII (Berlin, 1905), 117-23.

About this page

APA citation. Schlager, P. (1910). Onno Klopp. In The Catholic Encyclopedia. New York: Robert Appleton Company.

MLA citation. Schlager, Patricius. "Onno Klopp." The Catholic Encyclopedia. Vol. 8. New York: Robert Appleton Company, 1910. <>.

Transcription. This article was transcribed for New Advent by Joseph P. Thomas.

Ecclesiastical approbation. Nihil Obstat. October 1, 1910. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York.

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