the following year. From 4 June 1976, he taught as a full professor of history, in particular medieval history, regional history and historical ancillary sciences, at the Julius-Maximilians-Universität Würzburg. In 2001 he was retired. His farewell lecture, in which he took a critical look at recent developments in German higher education, was held on 16 June 2001 at a symposium in the . Main areas of research Herde works in the field of medieval and modern history, especially on the history of the empire and the papacy of the later Middle Ages, on the social and intellectual history of Italian humanism and on the intellectual history of the Risorgimento. His further research interests include the auxiliary sciences of history, the Bavarian and the history of the Second World War. His Munich dissertation, first published in 1961, also received great international acclaim. The work was published in 1967 in a second improved and extended edition and became a standard work of papal diplomacy of the 13th century. With the edition and investigation of the formula books of the Audientia litterarum contradictarum he published a two-volume and almost 1400-page Munich habilitation thesis. The work was methodologically innovative, since Herde linked questions of document science and canonism. Herde conducted research on late medieval papal documents, on the history of Italy, especially Florence in the Renaissance and the history of Sicily. About Charles I of Anjou Herde published an extensive article in the Dizionario Biografico degli Italiani. This study on the first Angevinen on the Sicilian throne resulted in a biography in 1979. In Würzburg, Herde dealt intensively with Franconian history and the history of the empire and pope in the 13th century. But Herde also devoted himself to problems of the 19th century. Among other things he examined the relations of Bavaria and the Holy See in the time of the beginning Kulturkampf. Herde published a standard work in 1981 with his biography of Pope Celestine V. The work was published in Italian translation in 2004 and was supplemented in 2008 by his Monumenta Germaniae Historica edition of the oldest vitae of "papa angelicus". With his work, published in 1986, Herde presented for the first time the history of medieval Ghibellines and Guelphs. Together with his student Thomas Frenz, he published in 2000 the letter and memorial book of the Passau Cathedral dean Albert von Behaim of 1246. Already in the 1980s, Herde