What event started World War I?

The assassination of Archduke Franz Ferdinand of Austria is widely recognized as the event that triggered the outbreak of World War I. On June 28, 1914, the archduke, heir to the Austro-Hungarian throne, was assassinated in Sarajevo by Gavrilo Princip, a member of the nationalist group known as the Black Hand. This act set off a chain reaction of political maneuvering, alliances, and hostilities among the major European powers.

The assassination led Austria-Hungary to issue an ultimatum to Serbia, where the assassin was connected. Serbia’s response was seen as inadequate, prompting Austria-Hungary to declare war on Serbia. This declaration activated a complex web of alliances, resulting in a rapid escalation of conflict involving multiple countries and leading to a global war.

Other options do not represent the starting point of World War I. The bombing of Pearl Harbor occurred much later in 1941 and was significant for starting the United States' involvement in World War II. The sinking of the Lusitania in 1915 contributed to growing tensions between the United States and Germany but did not directly initiate the war. The invasion of Poland by Germany, which marked the beginning of World War II, happened in 193