Linguistic, archaeological, and mythological evidence indicates that Siwais migrated to Bougainville from New Guinea and have lived in and around their present location for at least 2,000 years and probably very much longer. They have close linguistic relations with Buin people to the south and, to a lesser extent, with Nagovisi people to the north. In precontact times contact with other linguistic groups was not great, though there was some intermarriage, trade (especially with the Alu and Mono islands in the Solomon Islands), and occasional warfare. Europeans traded intermittently and inDirectly with the Siwai coast in the last two decades of the nineteenth century, but beyond steel tools there was minimal trade until well into the twentieth century. Around the turn of the century, a small number of men worked on distant plantations and brought back new plants; others were introduced in the period of German administration. Colonial administration effectively reached Siwai after 1919 when an Australian administration post was set up on the Buin coast. In the early 1920s, both the Catholic and Methodist missions set up stations in Siwai and in the years before World War II there was a small amount of trade in copra, most people were converted to Christianity, monetization followed the imposition of taxation, and most adult men were employed for substantial periods as plantation laborers, mainly on the east coast of the island. Cultural change was more rapid in the postwar years: cash cropping, especially of cocoa, became important; education became almost universal and continued to the tertiary level; traditions were transformed; a massive Copper mine (Panguna) was constructed 50 kilometers away, introducing new forms of employment; alien political institutions were introduced; and Siwai became part of an independent Papua New Guinea in 1975.