Gavrilo Princip, (born July 25 [July 13, Old Style], 1894, Obljaj, Bosnia—died April 28, 1918, Theresienstadt, Austria), South Slav nationalist who assassinated Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his consort, Sophie, Duchess von Hohenberg (née Chotek), at Sarajevo, Bosnia, on June 28, 1914. Princip’s act gave Austria-Hungary the excuse that it had sought for opening hostilities against Serbia and thus precipitated World War I. In Yugoslavia—the South Slav state that he had envisioned—Princip came to be regarded as a national hero.

Born into a Bosnian Serb peasant family, Princip was trained in terrorism by the Serbian secret society known as the Black Hand (true name Ujedinjenje ili Smrt, “Union or Death”). Wanting to destroy Austro-Hungarian rule in the Balkans and to unite the South Slav peoples into a federal nation, he believed that the first step must be the assassination of a member of the Habsburg imperial family or a high official of the government.

Having learned that Franz Ferdinand, as inspector general of the imperial army, would pay an official visit to Sarajevo in June 1914, Princip, his associate Nedjelko Cabrinovic, and four other revolutionaries awaited the archduke’s procession on June 28. Cabrinovic threw a bomb that bounced off the archduke’s car and exploded beneath the next vehicle. A short time later, while driving to a hospital to visit an officer wounded by the bomb, Franz Ferdinand and Sophie were shot to death by Princip, who said he had aimed not at the duchess but at General Oskar Potiorek, military governor of Bosnia. Austria-Hungary held Serbia responsible and declared war July 28.

After a trial in Sarajevo, Princip was sentenced (October 28, 1914) to 20 years’ imprisonment, the maximum penalty allowed for a person under the age of 20 on the day of his crime. Probably tubercular before his imprisonment, Princip underwent amputation of an arm because of tuberculosis of the bone and died in a hospital near his prison.