Boris Vasilkovich (; 1231âÂÂ1277) was Prince of Rostov from 1238 until his death in 1277. He was the elder of the two sons of Vasilko Konstantinovich.
Boris was born in 1231. He was the elder of the two sons of Vasilko Konstantinovich and his wife Maria of Chernigov. His father was killed at the battle of Sit River in 1238, and Boris ascended the throne of Rostov along with his younger brother Gleb. In 1244, Boris received the charter for the throne from Batu Khan.
Boris visited Sartak Khan twice, in 1245 and 1250, and bestowed gifts upon Ulaghchi in 1256 and 1257. Following his trip to the Golden Horde in 1258, he accompanied the Mongol census-takers to Novgorod. In 1277, at the request of the khan Mengu-Timur, Boris took part in the Mongol campaign against the Alans; however, he fell ill and died on 16 September. He was buried in the Assumption Cathedral in Rostov. His younger brother Gleb, who had received Beloozero as an appanage, succeeded him in Rostov; however, he died a year later, and Boris's two eldest sons, Dmitry and Konstantin, became joint rulers.
In 1248, Boris married Maria Yaroslavna of Murom. They had three sons: Dmitry, Konstantin, and Vasily.