Domains (tana) in Tana ’Ai are the highest order of the classificatory categories of Tana ’Ai society. They are, in the broadest sense, religious in nature and ceremonial in manifestation. Leadership in a tana is, or was until recently, exercised mainly in the realm of sacred authority and ritual performance and the tana had no single secular authority. The Tana ’Ai pattern is best illustrated by features of the domain of Wai Brama, the largest of the tana of Tana ’Ai. In Wai Brama the most important decisions affecting the secular affairs of the domain’s clans and houses are taken by the ina geté (‘great mothers’) of those clans and houses while men, as ritual specialists, carry out domain rituals on behalf of their sisters and mothers. As a society, Tana Wai Brama is defined by the relations of the clans which provide their members with land in the domain by virtue of the clans’ positions in a system of precedence set out in the domain’s myths of origin. ^[5]

Tana Wai Brama is a ceremonial domain headed by a tana pu’an, a ‘source of the domain’, who is always of the central house of the central clan in terms of the precedence of clans in the domain and houses in the clan. The central clan is credited with founding the domain in the mythic past. The tana pu’an is the head of a ceremonial system within which the clans of the tana must help organise, provision and conduct rituals of the domain. These rituals are the gren mahé and the rituals to open and close the dry and wet seasons. ^[6] It is important to note that it is clan membership that entitles, indeed, requires, a person to discharge obligations in gren mahé, regardless of whether he or she resides at a place clearly within the domain’s territory. Given that the clans are not themselves associated with demarcated territories, neither the clans of the domain nor the tana as a whole can be described strictly as territorial institutions. A tana is instead a loosely organised region defined by a centre, whose peripheries form no clear boundary. A tana’s centre is defined ritually (if not geographically) by its mahé, the domain’s central ceremonial site, and socially by the ceremonial office of the tana pu’an. Notwithstanding the delimitation of domain boundaries in Map 1, the domains are best thought of as social spaces defined by ritual centres whose influence and power extend radially and outwards until overshadowed by the power of neighbouring domains radiating from their centres. Thus, a person living on the frontier of two tana might have obligations in one gren by virtue of clan membership while participating in the gren of the other tana as a way of hedging his or her bets with respect to the fertility of gardens (which the gren ensures) or because he or she traces ancestral origins to a clan of that tana.