Tensions had been brewing throughout Europe—especially in the troubled Balkan region of southeast Europe—for years before World War I actually broke out. A number of alliances involvi… See more

Because mighty Russia supported Serbia, Austria-Hungary waited to declare war until its leaders received assurance from German leader Kaiser Wilhelm IIthat Germany would support th… See more

In the First Battle of the Marne, fought from September 6-9, 1914, French and British forces confronted the invading Germany army, which had by then penetrated deep into north… See more

On the Eastern Front of World War I, Russian forces invaded the German-held regions of East Prussia and Poland, but were stopped short by Ger… See more

At the outbreak of fighting in 1914, the United States remained on the sidelines of World War I, adopting the policy of neutrality favored by President Woodrow Wilsonwhile continuing to engage in commerce and shipping wit… See more

According to an aggressive military strategy known as the Schlieffen Plan (named for its mastermind, German Field Marshal Alfred von Schlieffen), Germany began fighting World War I on two fronts, invading France through n… See more

The bloodshed on the battlefields of the Western Front, and the difficulties its soldiers had for years after the fighting had ended, inspired such works of art as “All Quiet on the Western Front… See more

From 1914 to 1916, Russia’s army mounted several offensives on World War I’s Eastern Front, but was unable to break through German lines. Defeat on the battlefield, combined with e… See more

With World War I having effectively settled into a stalemate in Europe, the Allies attempted to score a victory against the Ottoman Empire, which entered the conflict on the side of the C… See more