Yaroslav was the son of Vladimir “The Great” and his third wife, Rogneda of Polotsk. As a youth, Yaroslav was sent by his father to rule the northern lands near Rostov. In 1010, Yaroslav served Novgorod as vice-regent.
However, relations with his father degraded over time, especially after Vladimir bequeathed the throne to his younger son Boris. In 1014, Yaroslav refused to pay tribute to his father. Only Vladimir’s death in 1015 prevented a war from being waged between father and son.
After Vladimir’s death, Yaroslav’s older brother Svyatopolk killed three of their younger brothers (including Boris) and seized power of Kievan Rus’. In 1016, with the help of Novgorod, Yaroslav defeated Svyatopolk’s troops near the town of Lyubech. Svyatopolk fled to Poland to the sanctuary of his father-in-law, Duke Bolaslaus I.
This victory, however, did not ensure a smooth reign for Yaroslav. In 1018, Svyatopolk returned with troops from Poland and seized Kiev. Again, Novgorod came to the rescue, and in 1019, Yaroslav wrested the throne back from Svyatopolk.
In 1019, Yaroslav married Ingegerd “Irene”, daughter of Olof Skötkonung of Sweden and Estrid of the Obotrites. Together, Yaroslav and Irene had five sons and five daughters, several of whom played an integral role in Yaroslav’s foreign policy, as he regarded dynastic marriages an excellent way to solidify connections with other countries. Yaroslav’s son Vsevolod wed a daughter of the Byzantine Emperor Konstantin Monomakh; his son Izyazlav married the sister of Kazamir of Poland Gertrude; daughter Anne of Kiev wed Henry I de France (my two-times 29th great-grandparents); daughter Elizabeth of Kiev married Harald III of Norway; and daughter Anastasia of Kiev wed the future Andrew I of Hungary.
In 1023, Yaroslav’s younger brother Mstislav rebelled, and Yaroslav fled to Novgorod. However, the Kievans were hostile to Mstislav, and he soon offered to Yaroslav joint rule of Kievan Rus’. Mstislav and Yaroslav divided the lands: Yaroslav received everything west of the Dnepr River, while Mstislav was granted all lands to the east. Yaroslav preferred to stay in Novgorod, moving back to Kiev in 1035, after Mstislav died without heirs. Again, Yaroslav controlled all of Kievan Rus’.
In 1037, Yaroslav defeated the Pincenates tribes, whose raids had been a long-lasting problem in the southern territories. To mark the victory, Yaroslav ordered that the Saint Sofia Cathedral be built.