Boris Konstantinovich

Boris Konstantinovich (; died 1394) was Grand Prince of Nizhny Novgorod-Suzdal in 1365 and from 1383 to 1392. He was the third son of Konstantin of Suzdal.

Reign Andrey was born around 1335. He was the third of the four sons of Konstantin of Suzdal. After his father's death in 1355, he received Gorodets. After his elder brother Andrey died childless in 1365, Boris sought to occupy the grand princely throne. His elder brother Dmitry, who was supposed to inherit the throne according to traditional succession practices, requested assistance from Grand Prince Dmitry of Moscow, who sent Sergius of Radonezh to persuade Boris to reconcile with his brother. However, Boris refused, which led to Dmitry of Moscow sending Muscovite forces to the aid of Dmitry.

Following the death of his brother Dmitry in 1383, Boris received the patent for the throne of Nizhny Novgorod-Suzdal. In 1391, Boris returned to his principality after receiving the patent for the throne from the khan; however, Vasily I of Moscow was able to purchase the charter for the entire principality from Tokhtamysh and the boyars of Nizhny Novgorod betrayed Boris by opening the city's gates to Muscovite forces in 1392, after which Nizhny Novgorod lost its independence. Boris may have retained his former title in 1393–1394 as a service prince. He died in 1394.

Family According to Russian chronicles, Boris married a daughter of Algirdas in 1354. She is named Agrypina in one chronicle.