Archeological evidence indicates that humans arrived on New Guinea at least 60,000 years ago, probably by sea from Southeast Asia during an Ice Age period when the sea was lower and distances between islands shorter. Although the first arrivals were hunters and gatherers, early evidence shows that people managed the forest environment to provide food. There also are indications of gardening having been practiced at the same time that agriculture was developing in Mesopotamia and Egypt. Early garden crops--many of which are indigenous--included sugarcane, Pacific bananas, yams, and taros, while sago and pandanus were two commonly exploited native forest crops. Today's staples--sweet potatoes and pigs--were later arrivals, but shellfish and fish have long been mainstays of coastal dwellers' diets.
When Europeans first arrived, inhabitants of New Guinea and nearby islands--while still relying on bone, wood, and stone tools--had a productive agricultural system. They traded along the coast, where products mainly were pottery, shell ornaments, and foodstuffs, and in the interior, where forest products were exchanged for shells and other sea products.
The first Europeans to sight New Guinea were probably the Portuguese and Spanish navigators sailing in the South Pacific in the early part of the 16th century. In 1526-27, Don Jorge de Meneses accidentally came upon the principal island and is credited with naming it "Papua," a Malay word for the frizzled quality of Melanesian hair. The term "New Guinea" was applied to the island in 1545 by a Spaniard, ê–igo Ortiz de Retes, because of a fancied resemblance between the islands' inhabitants and those found on the African Guinea coast. Although European navigators visited the islands and explored their coastlines for the next 170 years, little was known of the inhabitants until the late 19th century.
With Europe's growing need for coconut oil, Godeffroy's of Hamburg, the largest trading firm in the Pacific, began trading for copra in the New Guinea Islands. In 1884, Germany formally took possession of the northeast quarter of the island and put its administration in the hands of a chartered company. In 1899, the German imperial government assumed direct control of the territory, thereafter known as German New Guinea. In 1914, Australian troops occupied German New Guinea, and it remained under Australian military control until 1921. The British Government, on behalf of the Commonwealth of Australia, assumed a mandate from the League of Nations for governing the Territory of New Guinea in 1920. It was administered under this mandate until the Japanese invasion in December 1941 brought about the suspension of Australian civil administration. Following the surrender of the Japanese in 1945, civil administration of Papua as well as New Guinea was restored, and under the Papua New Guinea Provisional Administration Act, 1945-46, Papua and New Guinea were combined in an administrative union.
On November 6, 1884, a British protectorate was proclaimed over the southern coast of New Guinea (the area called Papua) and its adjacent islands. The protectorate, called British New Guinea, was annexed outright on September 4, 1888. The possession was placed under the authority of the Commonwealth of Australia in 1902. Following the passage of the Papua Act of 1905, British New Guinea became the Territory of Papua, and formal Australian administration began in 1906. Papua was administered under the Papua Act until the Japanese invaded the northern parts of the islands in1941 and began to advance on Port Moresby and civil administration was suspended. During the war, Papua was governed by a military administration from Port Moresby, where Gen. Douglas MacArthur occasionally made his headquarters. As noted, it was later joined in an administrative union with New Guinea during 1945-46 following the surrender of Japan.
The Papua and New Guinea Act of 1949 formally approved the placing of New Guinea under the international trusteeship system and confirmed the administrative union of New Guinea and Papua under the title of "The Territory of Papua and New Guinea." The act provided for a Legislative Council (established in 1951), a judicial organization, a public service, and a system of local government. A House of Assembly replaced the Legislative Council in 1963, and the first House of Assembly opened on June 8, 1964. In 1972, the name of the territory was changed to Papua New Guinea.
Elections in 1972 resulted in the formation of a ministry headed by Chief Minister Michael Somare, who pledged to lead the country to self-government and then to independence. Papua New Guinea became self-governing in December 1973 and achieved independence on September 16, 1975. The 1977 national elections confirmed Michael Somare as Prime Minister at the head of a coalition led by the Pangu Party. However, his government lost a vote of confidence in 1980 and was replaced by a new cabinet headed by Sir Julius Chan as Prime Minister. The 1982 elections increased Pangu's plurality, and parliament again chose Somare as Prime Minister. In November 1985, the Somare government lost a vote of no confidence, and the parliamentary majority elected Paias Wingti, at the head of a five-party coalition, as Prime Minister. A coalition, headed by Wingti, was victorious in very close elections in July 1987. In July 1988, a no-confidence vote toppled Wingti and brought to power Rabbie Namaliu, who a few weeks earlier had replaced Somare as leader of the Pangu Party.
Such reversals of fortune and a revolving-door succession of Prime Ministers continue to characterize Papua New Guinea's national politics. A plethora of political parties, coalition governments, shifting party loyalties and motions of no confidence in the leadership all lend an air of instability to political proceedings. For the first 27 years of independence, a "first past the post" electoral system resulted in many parliamentarians elected with less than 15 percent of their constituency. Fractious politics and a 75% loss rate for incumbents precluded the development of strong political parties or a stable national leadership. Many hope that limited preferential voting, introduced in 2003, and an organic law on political parties will stabilize national politics.
One of the key developments in PNG's recent history was the establishment of the Independent Commission Against Corruption (ICAC) in 2002. The ICAC was established to investigate and prosecute corruption cases, which had been a major issue in PNG. The commission was initially successful in prosecuting a number of high-profile cases, but its effectiveness has been called into question in recent years.
In 2007, the government launched the Vision 2050 initiative, which aimed to create a long-term development plan for the country. The plan focused on areas such as education, health, infrastructure, and the environment, and aimed to promote sustainable economic growth and development. However, the implementation of the plan has been slow, and many of its goals remain unmet.
In 2011, PNG hosted the Pacific Games, which were seen as a symbol of the country's progress and development. The event was successful in terms of organization and infrastructure, and helped to boost tourism and international relations. However, the cost of hosting the games was high, and some criticized the government for prioritizing the event over other pressing issues.
Political instability has continued to be a major issue in PNG, with numerous changes of government and periods of unrest. In 2017, the Supreme Court ruled that the election of Prime Minister Peter O'Neill was unconstitutional, but O'Neill refused to step down and instead called for a state of emergency. The situation was eventually resolved through negotiations, but it highlighted the ongoing challenges of political stability in PNG.
In recent years, PNG has also faced economic challenges, including a decline in global commodity prices and a lack of investment in key industries such as agriculture and manufacturing. In 2018, the government declared a state of emergency in the country's health system, citing a lack of funding and resources.