Konchak Agafia

[While Michael was asserting his authority, his rival Yury of Moscow ingratiated himself into the favor of Uzbeg so that he appointed him chief of the Rus' princes, and gave him his sister, Konchak, in marriage. Having been three years at Uzbeg's court, Yury returned with an army of Mongols and Mordvins. After he ravaged the villages of Tver, Yury was defeated by Mikhail in December 1318, and his new wife and the Mongol general, Kawgady, were captured. While she stayed in Tver, Konchak, who converted to Christianity and adopted the name Agatha, died. Mikhail's rivals suggested to Uzbeg Khan that he had poisoned the Khan's sister and revolted against his rule. Mikahil was summoned to Sarai and executed on November 22, 1318.[56] In 1322, Mikhail's son, Dmitry, seeking revenge for his father's murder, went to Sarai and persuaded the Khan that Yury had appropriated a large portion of the tribute due to the Horde. Yury was summoned to the Horde for a trial but, before any formal investigation, was killed by Dmitry. Eight months later, Dmitry was also executed in the Horde for his crime.] https://www.podgorski.com/main/khanate-golden-horde.html