Simplify the following text for a Grade 8 native English-speaking person.
Original: The account that he gave in his first autobiography , accepted for several years , is that he was a Sherpa born and brought up in Tengboche , Khumbu in northeastern Nepal .
Simplified: The account that he gave in his first autobiography , accepted for several years , is that he was a Sherpa born and brought up in Khumbu in Nepal .