A large-scale campaign of professional assassination conducted between two Great Houses of the Landsraad under the formal rules of the Great Convention. Since atomic weapons were outlawed and shields nullified projectile weapons, the Great Houses resorted to treachery and professional killers to pursue their vendettas. Each House employed a master assassin, often Mentat-trained, to oversee both offence and defence. The most consequential War of Assassins was the Harkonnen campaign against House Atreides on Arrakis in 10191, which ultimately led to the fall of the Corrino Empire.