Yaroslav I the Wise (978-1054) – founder of Yaroslavl. Yaroslav was thrice Grand Prince of Novgorod and Kiev, uniting the two principalities for a time under his rule. During his lengthy reign, Kievan Rus' reached a zenith of its cultural flowering and military power.
Early years of Yaroslav's life are enshrouded in mystery. He was one of the numerous sons of Vladimir the Great, presumably his second by Rogneda of Polotsk. In his youth, Yaroslav was sent by his father to rule the northern lands around Rostov the Great but was transferred to Novgorod the Great, as befitted a senior heir to the throne, in 1010. While living there, he founded the town of Yaroslavl on the Volga.
Yaroslav promulgated the first code of laws in the East Slavic lands, the Yaroslav's Justice, better known as Russkaya Pravda. He sponsored the construction of the Saint Sophia Cathedral in 1037. Other celebrated monuments of his reign, such as the Golden Gates of Kiev, have since perished. Yaroslav was a notable patron of book culture and learning. In 1051, he had a Russian monk Ilarion proclaimed the metropolitan of Kiev, thus challenging old Byzantine tradition of placing Greeks on the episcopal sees. Ilarion's discourse on Yaroslav and his father Vladimir is frequently cited as the first work of Old Russian literature.