Note 18 — Chapter XI · FREDERICK BARBAROSSA AND ALEXANDER III. THE RENEWED CONFLICT OF PAPACY AND EMPIRE (1152–1190).[18]

Among the modern authorities for this period may be quoted Prutz’s Kaiser Friedrich I., Reuter’s Geschichte Alexanders des Dritten und der Kirche seiner Zeit, and Ficker’s Forschungen zur Reichs- und Rechtsgeschichte in Italien. Giesebrecht’s great work, unluckily, ends with the fall of Henry the Lion. Raumer’s Geschichte der Hohenstaufen is quite antiquated. A full account of Frederick’s Italian struggle is to be found in English in Testa’s History of the War of Frederick I. against the Communes of Lombardy (1877). Otto of Freising is a first-rate original chronicler.