Simplify the following text for a Grade 8 native English-speaking person.
Original: Nikolaus ` Klaus ' Barbie ( October 25 , 1913 â `` September 25 , 1991 ) was an SS-Hauptsturmf Ã 1\/4 hrer ( rank approximately equivalent to army captain ) , Gestapo member and war criminal .
Simplified: Klaus Barbie ( October 25 , 1913 â `` September 25 , 1991 ) was an SS-Hauptsturmf Ã 1\/4 hrer , soldier , and Gestapo member .