U-Boat

1 Gavrilo Princip
2 Assassinating Archduke Franz Ferdinand
3 Triple Alliance
4 Triple Entente
5 The Schlieffen Plan
6 Kaiser Wilhelm
7 The Ottomans
8 War in the Balkans
9 July Crisis
10 Miracle of the Marne
11 Verdun
12 The Somme
13 Czar Nicholas
14 October Revolution
15 Jutland
16 U-Boat
17 The Lusitania
18 March 1918 Offensive
19 American Expeditionary Force
20 Hundred Day Offensive
21 Passchendaele
22 Zimmermann Telegram
23 Treaty of Versailles
24 Spanish Influenza