Catholic Encyclopedia (1913)/Thegan (Degan) of Treves
Chronicler, d. about 850. Very little is known of his life; all that is certain is that he was assistant Bishop of Trier and was a warm friend of Walafrid Strabo. These facts are learned from some letters and verses still in existence. It cannot be positively determined whether he is identical with Theganbert, provost of the Monastery of St. Cassius at Bonn, who placed the relics of Sts. Chrysanthus and Daria in the church at Munstereifel. He wrote a history of Louis the Pious, "Vita Ludovici imperatoris", an unsatisfactory narrative written in the form of scanty annals. It begins with St. Arnulf of Metz, describes the vicissitudes of the brothers of Louis, and gives a more detailed account of Louis's reign during the years 814-835. The later narrative is probably by another author. Strabo wrote an introduction to the chronicle. The narrative is very partisan, as the merits of Louis are exalted while the actions of Lothair and of a number of bishops, especially of Bishop Bbo of Reims, are severely criticised. The best edition of this work is that of Pertz in the "Mon. Germ. His.: Scriptores", II, 585-604. It was also published in P.L., CVI, 405-428, and was translated into German by Jasmund (Berlin, 1850) and by Wattenbach (Leipzig, 1889).
SIMSON, Ueber Thegan, den Geschichtsschreiber Ludwigs des Frommen (Gottingen, 1870); WATTENBACH, Geschichtsquellen, I (Berlin, 1893), 208 sq.; POTTHAST, Bibliotheca (Berlin, 1896), 1049.