The traditional system of political and social relations called adat is more than a norm to which events tended to conform in the past. It is also invested with high moral value, so that right behaviour according to adat is often spoken of in the same terms as right religious conduct, and this view is embodied in the sayings. The Malay population of Negri Sembilan claim descent from immigrants from Minangkabau. The emergence of Negri Sembilan as a political unit may be dated from 1773, when Raja Melewar, a prince of the Minangkabau ruling house at Pagar Ruyong, was invited to become ruler, and founded the dynasty which still occupies the throne. The sumptuary rules and perqmsites of the Ruler were important as symbols. Certain items of regalia, styles of housebuilding and decoration were his exclusive prerogatives. Adat varies between the constituent parts of Negri Sembilan, and local experts speak of these variations as highly important.