This paper's original impetus was to attempt to find the morphosyntactic origins of the well-known Polynesian o and a possessive-markers, and the origins of the phonologically and grammatically similar Rotuman markers ?o and ?e. In exploring these origins, some contribution is made to the development of the Oceanic possessive system in Proto-Central Pacific as a whole, and especially within the Fiji dialect chain. In particular, evidence is adduced to suggest that the Polynesian and Rotuman systems resemble those of Kadavu and Gone Dau more than those of Lau, and that this suggests that Geraghty's (1983) Tokalau-Polynesian may require some reassessment. 1. INTRODUCTION. Proto-Polynesian (PPn) and Rotuman both have possessive-marking systems that appear not to continue directly the Proto-Oceanic (POc) or Proto-Central Pacific (PCP) systems but that, on the surface at least, look very similar to each other. The well-known alo distinction, which is not found outside Polynesia/Rotuma, has received a great deal of attention in the linguistic literature. But almost all of this attention has focused on the semantics of a- and omarking. It is somewhat surprising that there has not been much discussion on the morphosyntactic history of these two markers. In this paper, I attempt to outline the historical development of the Polynesian and Rotuman possessive-marking systems, and also to cast some light on developments within Fiji itself. In so doing, I will suggest that the Central Pacific linkage may well be part of the Southern Oceanic linkage, most closely related to the languages of Northern Vanuatu.I 2. SUBGROUPING HYPOTHESES. The Central Pacific subgroup of Oceanic consists of the Fijian dialect chain, Rotuman, and the Polynesian languages. As far as external relationships are concerned, Pawley's (I972) Oceanic hypothesis (figure I) suggested that the closest relatives of Central Pacific are the languages of North and Central Vanuatu.2 Pawley subsequently withdrew the Southeast Solomonic group from Eastern Oceanic, and renamed the