Yaroslav II was the son
of Grand Prince Vsevolod III
of Russia, and came to the throne himself in 1238
on the death of his older brother Yuri II
fighting the Mongol
s under who were attacking the capital
city of Vladimir. (Yaroslav was off on a different military campaign in the west at the time.)
The Mongols overran Russia, and Yaroslav was the first ruler under what the Russians called "The Tatar Yoke"; he had to go to the great khan's city (Karakorum, in the Mongols' home territory) to have his position as grand prince confirmed, recieving the "yarlik" (official decree) from the khan. His first trip was shortly after his brother died, but he was forced to make a second trip and died in 1246 on his way back. He was succeeded by his younger brother Sviatoslav III.