The First World War resulted from festering imperial rivalries and ethnic conflicts in central Europe that set in motion a series of disastrous events and decisions. Europe had developed a system of alliances that divided the continent in two. Democratic Britain and France, along with the Russian Empire, had formed the Triple Entente. Central Powers were comprised of the new German Empire, Austria-Hungary, and Italy. The assassination of the heir to the Austro-Hungarian throne by a Serbian nationalist triggered the world war in August 1914.