Agafia Svyatoslavna of Rus was Princess of Masovia by her marriage to Duke Konrad I. She was a member of the Olgovichi clan. Wikipedia
Born: December 31, 1189, Principality of Novgorod-Seversk
Died: 1248 (age 58 years)
Grandchildren: Władysław I Łokietek, Leszek II the Black, Henryk IV Probus, and more
Children: Siemowit I of Masovia, Casimir I of Kuyavia, Bolesław I of Masovia, and more
Spouse: Konrad I of Masovia (m. 1207–1247)
Parents: Svyatoslav III Igorevich