In days gone by some of the Motu-speaking peoples around Port Moresby used to go on annual trading expeditions to the Gulf of Papua. There they would exchange with the inhabitants of that area pots and other valuables for sago and canoe logs. These expeditions were called hiri, and were not only spectacular in terms of the number, nature and size of the sailing craft involved and the cargoes they carried but also very important economically and in other ways to the Motu and others directly or indirectly involved.
For over forty years, archaeologists working along Papua New Guinea’s southern coastline have sought evidence for early ceramics and its relationship with Lapita wares of Island Melanesia. Failing to find any such evidence of pottery more than 2000 BP, and largely based on the excavation of eight early pottery-bearing sites during the late 1960s into the early 1970s, synchronous colonization some 2000 BP along 500km of the south Papuan coastline by post-Lapita ceramic manufacturers has been posited.