All Everests alive today can be traced back to one man, Roger Everest. He and his brother came over with William The Conquorer. Their name was Devereaux, but it was anglified to Everest, so was essentially an invented name. Roger and his brother were the first ever Everests. Roger's brother's blood line died out, which means, given that Roger and his brother were the first ever Everests and that Roger's brother has no descendents, we can all be traced back, in a a pretty much straight line, all the way back to Roger Everest. Roger's name appears in the doomsday book of 1086.