The immediate cause of World War I was the assassination of Archduke Franz Ferdinand of Austria by a Bosnian Serb student in June 1914. This caused a conflict between Austria-Hungary and Serbia, which in turn resulted in a series of events leading to the outbreak of the war. In the late 19th century and early 20th century, a number of factors contributed to the start of the war, including the rise of nationalism throughout Europe, the increasing power of military forces and the arms race, the colonial struggles of the European empires, a series of alliances between European powers, and the crises in the Balkans. All of these events created tensions and increased the likelihood of a conflict that would eventually become the First World War.