He led the soldiers of Prince Yaroslav of Kievan Rus

Another interesting fact about Harald Hardrada is that he led the soldiers of Prince Yaroslav of Kievan Rus. Following his defeat at the Battle of Stiklestad, Harald managed to flee to an isolated farm in Eastern Norway with the assistance of Rögnvald Brusason. He stayed for a while to cure his wounds before traveling north through the mountains to Sweden (perhaps up to a month later). Harald came in Kievan Rus a year after the Battle of Stiklestad. He most likely spent some time at the town of Staraya Ladoga (Aldeigjuborg), where he arrived in the first half of 1031. Grand Prince Yaroslav the Wise, whose wife Ingegerd was a distant relative of Harald, greeted Harald and his warriors.

In desperate need of military leaders, Yaroslav recognized Harald's military aptitude and appointed him captain of his soldiers. Olaf Haraldsson, Harald's brother, had previously been in exile in Yaroslav during the insurrection in 1028, and Morkinskinna claims that Yaroslav accepted Harald first and foremost because he was Olaf's brother. Harald participated in Yaroslav's expedition against the Poles in 1031, and may also have fought against other 1030s Kievan opponents and competitors such as the Chudes in Estonia, the Byzantines, the Pechenegs, and other steppe nomad populations.