The islands of the southwest Pacific have been peopled for millennia. The New Guinea mainland was occupied some 40 000 years ago (Groube et al. 1986), tuber and tree crops being curated in the central highlands as early as 30 000 BP (Gosden 1992), and systematic agriculture developing during the seventh millennium BC (White, Crook et al. 1970; White and O'Connell 1982: 171–212; Shutler 1970: 39–46; Golson 1981: 55–64, cf. Bellwood 1978; Swadling and Kaidoga 1981). Today Melanesia comprises hundreds of linguistic and cultural groups scattered from western Irian Jaya to Fiji. It is an incredibly complex tapestry of small-scale, ‘stateless’ societies, which has resulted from the peculiarities of geography, many adventures in migration and, more to the point of this present study, from countless undocumented tribal conflicts and alliances. Although Melanesian technologies were comparatively elementary, people were skilled in the use of stone, wood, bark, bone, shell and sometimes potting clay; and their tools enabled them, not only to garden effectively, but to hunt and domesticate animals. In various quarters they engineered impressive house structures and bridges (Kembol et al. [1974]), erected megaliths and small artificial islands (Reisenfeld 1950; Ivens 1930); they also developed lines and systems of exchange, sometimes with special trade languages and maritime expeditions involved (Malinowski [1922] 1961; Brookfield and Dart 1971; Hughes 1977; Specht 1978; Dutton 1982).