Vladimir I Sviatoslavich the Great

Vladimir I Sviatoslavich, called the Great (c. 958–1015), was prince of Novgorod from 970 and grand prince of Kiev from 978, the ruler who turned Rus' to Christianity. After Yaropolk murdered their brother Oleg in 977, Vladimir fled abroad, gathered a Varangian army and deposed Yaropolk in 978.

A thorough pagan, said to keep eight hundred concubines, he raised a shrine in Kiev to six gods headed by Perun. He sent envoys to test the faiths; at Constantinople they reported knowing not whether they were in Heaven or on Earth. In 988 he accepted Byzantine Christianity, married Emperor Basil II's sister Anna, and Christianized Rus'.

He founded the Church of the Tithes and installed his twelve sons over his principalities. In 1014 his son Yaroslav stopped paying tribute; Vladimir was gathering troops against him when he died on 15 July 1015. Both the Catholic and Orthodox churches canonized him.