The Shadow Schism encapsulates the formation of House Thuranni. When Elar Thuranni d'Phiarlan of the Thuranni family within House Phiarlan discovered that Tolar Paelion d'Phiarlan of the Paelion family was plotting on murdering the heads of the Five Nations during the Last War, Elar struck fast and murdered the entire family. When the Thuranni family was banished from House Phiarlan for their supposed treachery, they struck out to form House Thuranni.