William I., _the Conqueror_. William II. (1087-1100). William III. William IV. William I., _Emperor of Germany_ (1861-88). William II., _Emperor of Germany_.
If considered desirable, the dates of the reigns can be added, as shown in the second and fifth of these names. This adds a certain clearness to the entry, though the catalogue is not meant to serve as an historical dictionary.
The last of the above selection of books is entered
=Marie-Antoinette=, _Queen_: Younghusband, Lady. Marie-Antoinette: her early youth. 1912
In assigning a place in the classified catalogue for this and similar books we are faced with the necessity for deciding whether they shall go in 923.1 (Biography of Sociology--Chief Rulers, Kings, Queens, etc.). By the Queen Victoria book it was shown that her letters were inseparable from the history of her reign, and the same view is taken of the biographical and other books above, as indicated by the numbers attached to the entries. If this is considered to be the better and more useful placing for a book dealing with a monarch, it is a moot point whether the lives of their consorts are not also to a large extent contributions to the histories of their periods, and warrant similar treatment, when this book would be numbered with others on the reign of Louis XVI. (944.035). A confirmation of this view is found in the _Subject-Index of the London Library_, where no references whatever to books on Marie-Antoinette are to be found under her name, as they are under Louis XVI., though this is no criterion for so dealing with books catalogued according to the principles laid down in these pages. In the classified catalogue the books can be entered at 944.035, and a reference given to it at 923.1.
Following out the contrary idea, the book upon Prince Henry the Navigator is not put with the Biography of Princes, but with the Biography of Travellers, Discovery.
We may take two books upon Popes at this point, though the method of treatment is virtually the same,
MCCARTHY, Justin. Pope Leo XIII. (_Public men of to-day_.) 1896 922.21 STEPHENS, W. R. W., _Dean_. Hildebrand and his times. (_Epochs of church hist._) map. 1888 922.21
Contrary also to the views expressed above, but with as good reason, these two books are not classified with Religion--History of the Roman Catholic Church, but with the Biography of Religion--Popes. The subject-entries for the dictionary catalogue are