German historian, author of the first general history of medieval Germany based on modern critical methods, and a student of Leopold von Ranke.

In 1857 Giesebrecht became professor at Königsberg and in 1862 succeeded Heinrich von Sybel at Munich. In Geschichte der deutschen Kaiserzeit, 6 vol. (1855–95; “History of the German Imperial Age,” completed by B. von Simson), Giesebrecht concerned himself with political and religious aspects, ignoring legal, social, economic, and constitutional history. His romantic view of the emperors aroused controversy, notably with Sybel. Other works include Jahrbücher des deutschen Reichs unter Otto II (1840; “Annals of the German Empire under Otto II”) and the restoration of the monastery records Annales Altahenses (1841).