In his youth, Yaroslav was sent by his father to rule the northern lands around Rostov but was transferred to Veliky Novgorod,[REF] as befitted a senior heir to the throne, in 1010.
During the next four years Yaroslav waged a complicated and bloody war for Kiev against his half-brother Sviatopolk I of Kiev, who was supported by his father-in-law, Duke Bolesław I Chrobry of Poland [REF].