ABSTRACT
In mainland South East Asia, particularly highland Burnla, Leach denlonstrated a structural differentiation between hill peoples and valley centred Buddhist peoples with regard to their political systen1s, which are articulated with ecology, kinship, and econonlY (Leach 1960). Leach suggests that though such structural differentiation has been maintained for centuries, localised 'ethnic' change has occurred when a hill population adopts, as they start to cultivate wet-rice and beconle Buddhist, the manners, dress, and language of the dominant Shan, a Tai group. In other parts of mainland South East Asia (e.g. northern Thailand, Laos, and southwestern Yunnan) where more powerful Tai states were established, the structural differentiation, withered away and non-Tai populations in the hills have been nlore fully incorporated into the dOlninant Tai political systelTIS (cf. Condonlinas 1990: 70)
In northern Thailand, the Khon Miiang established a powerful kingdonl during the late thirteenth century, centred in the Chiang Mai basin, and holding sway over the Khon Miiang chiefs in other valleys and basins until the beginning of this century, despite the interruption to their overall hegemony during the Burnlese occupation in the sixteenth to eighteenth centuries. The political power of the Chiang Mai nlonarchy was based on control over political spaces called 11liiang, which closely correspond to alluvial plains as ecological units where Khon Miiang and other Tai groups cultivate wet-rice. The 11liiang has had a particular significance for the selfidentification of the Khon Miiang as belonging to a n1iiang donlain.
