Brief, but to start it off:
Barbarossa, The German Russian Conflict 1941-1945, by Alan Clark
Why the Allies Won, by Richard Overy
A Peace to End All Peace, The Fall of the Ottoman Empire and the Creation of the Modern Middle East, by David Fromkin
The Decline and Fall of the Roman Empire, by Edward Gibbon
The Gathering Storm, by Winston Churchill
Barbarossa, The German Russian Conflict 1941-1945, by Alan Clark
Why the Allies Won, by Richard Overy
A Peace to End All Peace, The Fall of the Ottoman Empire and the Creation of the Modern Middle East, by David Fromkin
The Decline and Fall of the Roman Empire, by Edward Gibbon
The Gathering Storm, by Winston Churchill
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