1914 CE

The assassination of Archduke Franz Ferdinand and his wife Sophie, Duchess of Hohenberg in Sarajevo by Gavrilo Princip triggers the July Crisis, leading to the outbreak of World War I; The Serbian campaign begins as Austria-Hungary invades Serbia, facing fierce resistance; The Battle of Liège sees German forces delayed by Belgian defenders, disrupting the Schlieffen Plan; The Battle of Tannenberg results in a decisive German victory over the Russian Second Army on the Eastern Front; The Siege of Tsingtao marks Japan’s entry into the war as Allied forces capture the German port in China; The First Battle of the Marne halts the German advance into France, beginning the prolonged stalemate of trench warfare on the Western Front.

In the 1910s, the 20th century.