Under which ruler did kievan russia achieve its greatest power?

Under "Yaroslav the Wise" in the 11th century. He build many buildings in Kiev (Kievan Russian) such as Cathedral of Saint Sophia. He also greatly helped to develop the culture and education of Kiev.

The native americans, spanish, french and americans all name places in our state. the word “arkansas” came from the quapaw indians, by way of early french explorers. at the time of the early french exploration, a tribe of indians, the quapaws, lived west of the mississippi and north of the arkansas river.