A visiting aristocrat is assassinated by a rebel separatist in the hosting vassal which sets off a diplomatic crisis. Entangled international alliances formed by aristocratic marriages over the previous decades are invoked. Within weeks, the major powers (Germany, Austria-Hungary, and Italy form the Centralist side and the United Kingdom, France, and Russia form the Triple Entente) are at war, and the conflict soon spreads around the world. Italy joins with the United States and Japan in an alliance with the Triple Entente, while Bulgaria and the Ottoman Empire join the Centralists. The resultant war shatters the aristocratic empires, frees their colonies, and leads to internal revolutions which depose the aristocrat families.