Simplify the following text for a Grade 7 native English-speaking person.
Original: Robert James Lee `` Bob '' Hawke AC GCL ( born 9 December 1929 ) was the 23rd Prime Minister of Australia and longest serving Australian Labor Party Prime Minister .
Simplified: Robert James Lee `` Bob '' Hawke ( born 9 December 1929 ) was the 23rd Prime Minister of Australia as leader of the Australian Labor Party . He was the third longest serving Prime Minister of Australia .