Simplify the following text for a Grade 6 native English-speaking person.
Original: Ernesto `` Che '' Guevara ( ; June 14 , 1928 â `` October 9 , 1967 ) , commonly known as El Che or simply Che , was an Argentine Marxist revolutionary , physician , author , intellectual , guerrilla leader , diplomat and military theorist .
Simplified: Ernesto Guevara de la Serna ( June 14 , 1928 - October 9 , 1967 ) was born in Argentina . He is commonly called Che Guevara or El Che .