The independent Melanesian island state of Solomon Islands (SI) lies immediately to the southeast of the PNG island province of North Solomons. Under an 1885 agreement between Britain and Germany, the North Solomons were to be in the German sphere of influence and the South Solomons in the British sphere of influence. Thus, Bougainville, Choiseul and Florida Islands, and a number of smaller islands, were in the German sphere of influence. However, after an adjustment of these boundaries following the Samoa Convention of 1899, Choiseul, Florida, and a number of smaller islands south of Bougainville, were added to the British sphere of influence and later included in the British Solomon Islands Protectorate. Ethnically, the people of SI’s Western province have much in common with the people of the PNG province of North Solomons.
In the early 20th century SI converts were brought into PNG to help European missionaries. In 1890 SI police constables were taken to Papua to help establish the Armed Native Constabulary. The British Solomon Islands Protectorate became the independent state of SI on 7 July 1978, adopted a modified form of the Westminster system with an elected National Parliament which elects the Prime Minister, and the monarch of Great Britain, represented by the Governor-General, as Head of State. The main political issue facing the new state was the question of devolution of powers to the provinces. The official language is English. Pidgin and local languages are also spoken. Some 95 percent of the population profess Christianity. Many also continue to hold traditional beliefs. In 1991 the population was an estimated 323,000. The capital is Honiara.
SI and PNG are both members of the South Pacific Commission and the South Pacific Forum and, together with Vanuatu, form the Melanesian Spearhead Group. In 1989 PNG and SI signed a border agreement which recognized the traditional rights of border residents, and a maritime and seabed boundaries pact. Tension arose between the two governments when fighting broke out between the rebel Bougainville Revolutionary Army (BRA) and the PNG Defence Force in the PNG province of North Solomons in 1989. PNG claimed that the SI government aided the rebels by allowing access, and arms, across the PNG/SI border. SI claimed that PNG had allowed its Defence Force soldiers to violate SI territory. In 1992 SI Prime Minister Mamoloni would not meet with PNG Prime Minister Namaliu to discuss the issue. In 1993 Billy Hilly, who succeeded Mamoloni as Prime Minister, negotiated with Paias Wingti, who succeeded Namaliu as Prime Minister. In August 1993 Billy Hilly announced that he would shut down the BRA office in Honiara. The move was welcomed by Australia and South Pacific Island states. In September 1993 PNG admitted that PNGDF soldiers had caused deaths and damage to property on SI territory and agreed to pay compensation.