Ворскла
Princes Troubetzkoy descend from Demetrius I Starshy, one of Algirdas's sons, who ruled the towns of Bryansk and Starodub. He was killed together with his elder sons in the Battle of the Vorskla River (1399). Demetrius's descendants continued to rule the town of Trubetsk (Troubchevsk) until the 1530s, when they had to convert to Roman Catholicism or leave their patrimony and settle in Moscow. They chose the latter, and were accepted with great ceremony at the court of Vasili III of Russia.