Konstantin Borisovich of Rostov

Konstantin Borisovich (1255-1307), younger son of Boris Vasilkovich of Rostov, went to the Golden Horde with his father in 1277 and, when Boris died there, served on Mengu-Timur's Alan campaign with his uncle Gleb, returning in 1278 to share Rostov with his brother Dmitry.

Driven out by Dmitry in 1281 and reconciled soon after, he received Rostov in the khan's partition of 1286, then exchanged it for Uglich about 1289. He regained Rostov on Dmitry's death in 1294, gave Uglich to his son Alexander and died at the Horde in 1307; in 1302 he had married a Tatar khan's daughter.