On June 28, 1914, two gunshots in the city of Sarajevo set off a chain reaction that would change the world.

In the first episode of the Moments That Shape Us World War I series, the story begins with the assassination of Archduke Franz Ferdinand and his wife by a young nationalist named Gavrilo Princip. What first appeared to be a political assassination quickly grew into something much larger as alliances across Europe began to activate.

This episode explores the tension already building across Europe, the rise of nationalism, and the complicated alliance system that turned a single event into the beginning of a global conflict. Within weeks, nations across the continent were declaring war, sending millions of soldiers into a fight they believed would be short.

Instead, the world was about to enter one of the deadliest conflicts in human history.