'Maria Borisovna of
Tver' (''Мария Борисовна'' in
Russian) (
1442? -
1467) was the first wife of
Grand Prince Ivan III and daughter of
Boris Alexandrovich of Tver.
When
Vasili II (Ivan III's father) was getting ready to attack
Dmitry Shemyaka, he found an ally in the person of Boris of Tver. The two decided to seal the alliance by arranging a
betrothal between the future Ivan III and Maria of Tver in
1452. It appears that she died from
poisoning in 1467. However, if one is to believe
Joseph Volotsky, she had been suffering from "infirmity" since childhood. She gave birth to
Ivan the Young in
1458.