from The American Heritage® Dictionary of the English Language, 4th Edition
- A medieval Slavic state that was the forerunner of modern Russia. Centered around the city of Kiev, it included most of present-day Ukraine and Belarus and part of northwest Russia. Kievan power and influence grew steadily through the 10th and 11th century, but was later weakened by internal disputes and fell to the Mongols by 1240.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. Dated form of Kievan Rus.
Sorry, no etymologies found.
As for the argument that a choice for Islam or Christianity would lead to satellite status, this is historically not tenable: a) despite the wide spread of Islam, this in no way prevented the formation of separate Moslem political entities; b) when Kievan Russia accepted Orthodox Christianity in the tenth century it did not become a client state of Byzantium.