Tony Abbott has lauded Malcolm Fraser as a fierce Australian patriot.
Mr Fraser died in the early hours of Friday, aged 84, five months after the death of his great political foe Gough Whitlam.
The prime minister cited the constitutional crisis of 1975 - in which both men were the leading political combatants - as one of the defining events of Australian history.
Mr Fraser held true to the belief that his actions were in the best interests of Australia, Mr Abbott said in a statement.
The friendship he built in later life with Mr Whitlam spoke volumes about the character of both men.
"In their own different ways, they were both fierce Australian patriots."
Mr Abbott paid tribute to many of Mr Fraser's achievements in government, including opposing apartheid, resettling Vietnamese refugees, advancing the lot of indigenous people, giving the Northern Territory self-government, and establishing the Australian Federal Police and freedom of information laws.
"He was rightly proud of his government," he said.
