Cecilia von Dithmarschen

According to the Lyubetskiy sinodik, Sviatoslav's wife was one Killikiya or Kelikia (Cecilia). On the other hand, German chroniclers write that his wife was Oda, a sister of Burchard, the Provost of Trier and she gave birth to one son. A portrait depicting Sviatoslav and his family in the Izbornik of 1073 shows that he had five sons and four of them were adults at the time their portrait was made. Based on these sources, it is obvious that Sviatoslav married twice. According to Dimnik, Sviatoslav married his first wife, Killikiya between 1043 and 1047. Their first child seems to have been a daughter, Vysheslava. Her eldest brother Gleb became prince of Tmutorakan and later of Novgorod. The second son of Sviatoslav and Killikiya was Oleg, the future prince of Chernigov. David, the future prince of Novgorod and Chernigov was born around 1051. Roman, who became prince of Tmutorakan, was born around 1052.

Sviatoslav married his second wife, Oda of Stade in about 1065. According to Dimnik. Oda, the daughter of Lothair Udo I, Margrave of the Nordmark, was in some way related to Henry III, Holy Roman Emperor. There is, however, no real evidence to support this claim. She gave birth to Sviatoslav's fifth son, Yaroslav, who later became prince of Murom and Chernigov. After Sviatoslav's death, Oda and her son moved to the Holy Roman Empire.

Sources:

• https://en.wikipedia.org/wiki/Sviatoslav_II_of_Kiev
• The Russian Primary Chronicle: Laurentian Text (Translated and edited by Samuel Hazzard Cross and Olgerd P. Sherbowitz-Wetzor) (1953). Medieval Academy of America. ISBN 978-0-915651-32-0.
• "The Narrative, Passion, and Encomium of Boris and Gleb" In Kantor, Marvin (1983). Medieval Slavic Lives of Saints and Princes. University of Michigan. ISBN 0-930042-44-1.
• Dimnik, Martin (1994). The Dynasty of Chernigov, 1054–1146. Pontifical Institute of Mediaeval Studies. ISBN 0-88844-116-9.
• Franklin, Simon; Shepard, Jonathan (1996). The Emergence of Rus 750–1200. Longman. ISBN 0-582-49091-X. Martin, Janet (1993). Medieval Russia, 980–1584. Cambridge University Press. ISBN 978-0-521-67636-6.
• Raffensperger, Christian (2012). Reimagining Europe: Kievan Rus' in the Medieval World. Harvard University Press. ISBN 978-0-674-06384-6.
• Vernadsky, George (1948). A History of Russia, Volume II: Kievan Russia. Yale University Press. ISBN 0-300-01647-6.