[4] A member of the Olelkovich family, he descended from Ruthenianized Eastern Orthodox branch of the Gediminid dynasty, and was a great-grandson of Algirdas, the grand duke of Lithuania.

He conducted an independent policy, fought with the Crimean Tatars, maintained close ties with the Principality of Moldavia, the Genoese colonies and the Principality of Theodoro in the Crimea.

However soon after, the Principality of Theodoro was conquered by the emerging Crimean Khanate.

He married Maria (d. 1501), daughter of Jonas Goštautas, by whom he had three children, Vasily Semyonovich [ru] (d. 1495), Alexandra, wife of Fedor Ivanovich Borovsky [ru], and Sophia (d. 1483), wife of Mikhail III of Tver, the last prince of Tver.

His son received the Principality of Pinsk as compensation, but he died young and was succeeded first by his mother, Maria, and then by his brother-in-law, Fedor, after her death.