Sineus and Truvor, according to the 12th-century Primary Chronicle, were the brothers of Rurik of the Varangian  Rus tribe. For a long time two names were believed to be a Slavic misunderstanding based on the Scandinavian expressions Trú vor ("our faithful") and Sine hus ("his households" or "his clan"). However, modern researches of old Scandinavian dialects demonstrate fallibility of that interpretation.