Peacock became External Territories Minister, responsible for PNG, on February 2, 1972, at just 32 years of age and was awarded the Grand Companion of the Logohu in 2006, which carries the title of Chief in PNG.
Upon being awarded the Grand Companion Peacock said: "I committed a lot of my life to Papua New Guinea, but it gave me much more back. And it's wonderful."
Australian Prime Minister Scott Morrison said that as the minister for external territories, Peacock built a close relationship with Sir Michael Somare and was instrumental in gaining Australian acceptance for Papua New Guinea independence.
"His bonds with Papua New Guinea were such that he visited PNG more than 50 times in his career," Morrison said.
Peacock is survived by his wife Penne and his daughters Ann, Jane and Caroline, his children with his first wife, the late Lady Susan Renouf.