Sineus and Truvor were the brothers of Rurik, a Varangian chieftain of the Rus' who is traditionally considered to be the founder of the Rurik dynasty. According to the Primary Chronicle, the brothers were invited by East Slavic and Finnic tribes to reign in northern Russia in 862. Sineus established himself at Beloozero and Truvor at Izborsk. After they died, Rurik consolidated their territories into his own.

Rurik was a Varangian chieftain of the Rus' who, according to tradition, was invited to reign in Novgorod in the year 862. The Primary Chronicle states that Rurik was succeeded by his kinsman Oleg who was regent for his infant son Igor.