Chapter 5. Austronesian Prehistory in Southeast Asia: Homeland, Expansion and Transformation Peter Bellwood Austronesian origins are here presented as an example of a frequent phenomenon in world prehistory, whereby populations who develop agriculture in regions of primary agricultural origins are provided with essential economic advantages over surrounding hunter-gatherers. These advantages allow them to undertake the colonization of very large regions, and the records of such colonizations are visible in the archaeological and linguistic records. The pattern of Austronesian expansion, possible reasons for it, and some major factors influencing subsequent differentiation of Austronesian cultures are all discussed, commencing from about 4000 BC in southern China and Taiwan. Questions of Ultimate Homeland This paper will commence by focusing on the question of where the immediate ancestor of Proto-Austronesian was located, and when. Proto-Austronesian is the hypothesized linguistic entity, perhaps a single language or perhaps a dialect network (see Pawley and Ross, this volume), ancestral to all subsequent and existing Austronesian languages. But like all languages it also had an ancestor, prior to the budding of the Austronesian (henceforth An) family as a linguistic taxon with its own unique history. An observation relevant for this question, one particularly intriguing in terms of its relevance for world prehistory, is that the general homeland regions of many of the major language families which have had long histories of association with agriculture seem to be geographically correlative with regions of primary (i.e. indigenously-generated) agricultural origins (Bellwood 1990b, 1991, in press b). In the Old World such language families include Indo-European, Elamo-Dravidian, Afro-Asiatic, Niger-Kordofanian, Nilo-Saharan, Sino-Tibetan, Austroasiatic, Thai-Kadai (or Daic of Ruhlen 1987) and Austronesian. The first two of these families, and possibly Afro-Asiatic, have arguable homelands in or closely adjacent to southwest Asia, the second two in northern sub-Saharan Africa, and the last three (with Sino-Tibetan being uncertain) in central and southern China. These three geographical regions are known from archaeological data to have witnessed major local developments of plant and animal domestication, in each case well before any such developments in intervening regions of the Old World (MacNeish 1992). Because of these widespread 103