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.