Simplify the following text for a Grade 6 native English-speaking person.
Original: Graham Arthur Chapman ( 8 January 1941 â `` 4 October 1989 ) was a British comedian , physician , writer , and actor and one of the six members of the Monty Python comedy troupe .
Simplified: Graham Chapman ( 8 January 1941 â `` 4 October 1989 ) was a British actor and writer .