User blog comment:Zippertrain85/Dawnguard Follow up./@comment-17114085-20131216013719/@comment-17114085-20131216024857

Ysgramor came with a huge army from Atmora, he didn't just kill the Snow Elves around Sarthal, he killed all the snow elves he could find. A few were able to hide from the angry atmoran like the ones from the Forgotten Vale. He wasn't a high kIng because the Dragon priests ruled back then, and in WIndhelm it states Harald was the first High King.