Svyatoslav Yaroslavich (1027—December 27, 1076) was the Prince (Knyaz) of Chernigov from 1054 to 1073 and Grand Prince Velikiy Knyaz of Kiev from 1073 until his death. A son of Yaroslav I the Wise, he was a founder of Chernigov princely line and is sometimes referred to as "Svyatoslav of Chernigov".
Upon his father's death in 1054, Svyatoslav joined his brothers Vsevolod and Iziaslav in forming a kind of a princely triumvirate that oversaw the affairs of Kievan Rus' until 1072. In 1067, they defeated their cousin, Vseslav of Polotsk, on the Nemiga river and took him prisoner. A year later, the brothers were smashed by the Polovtsi on the Alta river . After a while, Svyatoslav returned to defeat the steppe people with a small force at the town of Snov , thus enhancing his prestige among the populace. A part of the first Russian legal code Russkaya Pravda is assigned to the brothers.
In 1073, the triumvirate broke up, when Svyatoslav, supported by his younger brother Vsevolod, dethroned and replaced his older brother Iziaslav on the Kievan throne. Three years later, Russian scribes compiled the so-called Izbornik Svyatoslava at his request. One of the oldest relics of the Old East Slavic language, the book is a compilation of articles on grammar, logic, poetics, church, sermons, riddles, and parables. One of the miniatures represents Svyatoslav himself, standing with his second wife Oda and a son. There is still a controversy as to Oda's parentage, but it is known that her uncles were Emperor Henry III and Pope Leo IX.
Svyatoslav's sons by Oda:
Seljuk Sultan Kilij Arslan II claimed to descend from one of Svyatoslav's daughters.
