Papua New Guineans all over the country have been expressing sorrow for a man many consider an embodiment of Melanesian values and a giant in PNG politics.
Prime Minister James Marape said PNG had lost a great statesman who served with distinction in academia, politics and business.
"I join with family friends and the people of East New Britain and and papua New Guinea in mourning his passing," Marape said.
New Ireland Governor and former Prime Minister Sir Julius Chan described Sir Rabbie as a man of formidable character and a man who easily gained the confidence of society at large.
Sir Rabbie Namaliu was born in 1947 in the newly created post-war Australian Territory of New Guinea.
He was one of the first students of the University of Papua New Guinea (UPNG) as the country transitioned from colonial rule to independence.
He went on to earn a masters degree at the University of Victoria, British Colombia and was later awarded an honorary Doctor of Laws.
Along with Mekere Morauta, Charles Lepani and Anthony Siaguru, a group popularly known as the 'Gang of Four', he helped shaped public policy and built the civil service.
Former President of Autonomous Bougainville Government (ABG) and the Deputy Chairman of the Constitutional Planning Committee in 1974, John Momis, described Sir Rabbie as a man of integrity.
"His death sees the tragic departure of yet another of the core group of people not only contributed in significant ways to the founding of Papua New Guinea but also continued to contribute...for almost 50 years," he said.
His entry into the realm of politics, came when he was appointed Private Secretary to Chief Minister Michael Somare a year before independence in 1974.
In 1982, he was elected member for Kokopo and appointed Foreign Minister.
On the international front, Sir Rabbie led with distinction building relations on both sides of the globe.
He continued to maintain strong relations with key members of ASEAN and as President of the African, Caribbean and Pacific (ACP) Council of Ministers and Co-President of the ACP/European Economic Community joint Council of Ministers, he signed the Third Lome Convention that allowed for the provision of aid and preferential trade arrangements with Europe markets.
The decade after independence was a period of global economic uncertainty.
The country was hit hard by low commodity prices in the preceding years and the effects impacted on local politics.
PNG was struggling to plug serious budgetary gaps whilst managing a civil unrest in Bougainville that resulted in the closure of the Panguna mine.
In 1988, just days after taking over as leader of Pangu Pati Sir Rabbie was elevated to the top post in a vote of no-confidence motion becoming PNG's fourth Prime Minister.
In an era characterized by political instability, Sir Rabbie survived as prime minister over the next four years, taking the Pangu led government into the elections in 1992.
His calm, consultative approach and willingness to accept fault, reminiscent of many traditional 'Big Men' in Melanesian cultures, earned him respect even years after his term as prime minister ended.
President of the Autonomous Bougainville Government and former BRA strongman Ishmael Toroama said for many years Sir Rabbie was blamed for sending troops to Bougainville to quell the unrest.
But he has also been one of the few who have accepted responsibility.
"As President of Bougainville and as the former Commander of the BRA, the admission by the late Sir Rabbie Namaliu has earned the forgiveness of the people of Bougainville," President Toroama said.
"Seldom has a leader of Sir Rabbie's calibre admitted in public their direct role in decisions that caused a genocidal war that resulted in the loss of tens of thousands of lives and destroyed a generation of people."
Arrangements are being made for a state funeral in the coming days.