The manuscript sources listed below have been used in this volume. The dates given indicate the materials consulted, not the full run of the various collections. After the name of the collection is its location, for which the following abbreviations are used:
|BA-MA||Bundesarchiv-Militärarchiv, Freiburg i. B.|
|GS||Geheimes Staatsarchiv Preussischer Kulturbesitz, Berlin-Dahlem|
|HHStA||Haus-, Hof- und Staatsarchiv, Vienna|
|PRO||Public Record Office, London and Kew Gardens|
|RA||The Royal Archives, Windsor Castle, Berks|
In addition, the following abbreviations have been used in describing the collections.
|FO||Foreign Office, London|
|GFO||German Foreign Office, Berlin|
|HA||Haus Archiv, Berlin|
Bauer Papers, BA. Colonel Hermann Bauer, General Staff officer.
|No. 16||Diary and correspondence with the crown prince (1916).|
|No. 18||Correspondence with Hindenburg (1918), Hindenburg to Wilhelm (1918).|
Below Papers, BA-MA. General Otto von Below, army commander in World War I.
|No. 2||Correspondence with Hans von Below (1920-33).|
|No. 35||Collanse in 1918.|
Beseler Papers, BA-MA. General Hans von Beseler.
|Nos. 53-55||Correspondence with his wife (1915-17); Count Bodgan von Hutten-Czapski to Wilhelm (1916).|
Bigelow Papers, New York Public Library, Manuscript Division. Poultney Bigelow, a childhood friend of the Kaiser's, resumed his friendship in the postwar years and had many contacts with members of the Hohenzollern family.