In November 1915, a German corporal in the 16th Bavarian Reserve Infantry Regiment left his billet in a two-story farmhouse near Fournes, not far behind the front lines in northern France, and walked into town. Instead of enjoying the traditional soldiers' comforts of visiting a brothel or purchasing cigarettes and schnapps, he spent four marks to buy a slender book about Berlin's cultural treasures. Referred to as"the artist" by his fellow message runners, he was a figure of amusement to them, partly because it was easy to get a rise out of him by declaring that the war was lost, and partly because he spent hours in the trenches hunched over newspapers and books during lulls in his duties.

This withdrawn infantryman had denounced the Christmas Truce of December 1914, when British and German soldiers fraternized for a day. The only living being he reserved his affection for was a white terrier that strayed across enemy lines and obeyed him unconditionally. Nor did his habits ever really change. Decades later, he would abandon his companions late in the evening to retire to the solitude of his study, where reading glasses, a book and a steaming pot of tea awaited him. When his girlfriend was once so indelicate as to intrude upon his reveries, she met with a tirade that sent her running red-faced down the hallway. A sign hanging outside, after all, adjured"Absolute Silence!" By the end of his life, when he had been abandoned by most of his retinue and staged his own Götterdämmerung, the only personal effects the invading Soviet soldiers found in his Berlin bunker were several dozen books.

Adolf Hitler may be better known to posterity for burning rather than cherishing books, but as Timothy W. Ryback observes in"Hitler's Private Library," he owned more than 16,000 volumes at his residences in Berlin and Munich, and at his alpine retreat on the Obersalzberg. Ryback, the author of"The Last Survivor," a study of the town of Dachau, has immersed himself in the remnants of Hitler's collection, which are mostly housed at the Library of Congress. In poring over Hitler's markings and marginalia, Ryback seeks to reconstruct the steps by which he created his mental map of the world. The result is a remarkably absorbing if not wholly persuasive book....