Sviatoslav III was the son of Grand Prince Vsevolod III
, and came to the throne himself in 1246
on the death of his older brother Yaroslav II
, who had been on the way back from his second trip to the Mongol
Khan, overlord of Russia, to confirm Yaroslav's title.
Unfortunately, Batu Khan, the local Mongol ruler under the authority of the Great Khan, did not approve of Sviatoslav, and sent Yaroslav's sons to the Great Khan. On their return two years later, Sviatoslav was deposed in favor of his nephew Andrei II, who became Grand Prince. Sviatoslav did not die until around 1253.