"Manobo" is the hispanicized form of "Manuvu," which, of course, means "people." The Manobo appear to be a remnant of the very first Austronesian invasion from Taiwan, predating peoples like the Ifugao of Luzon. The Manobo supergroup includes several of the groups described elsewhere (see Bagobo, Hiligaynon, Bukidnon), but there are also many Manobo peoples not considered apart from the main group. The general orientation is now predominantly upland, as they were chased from the valleys by invading Visayans and Spaniards. But the Manobo have an adaptation to virtually every ecological niche, from rugged highland to coast, and are found from Sarangani Island to Agusan del Sur, the Davao provinces, Bukidnon, and North and South Cotabato. Kinship is figured bilaterally, and nuclear households are kin-grouped into widely dispersed communities usually situated on ridges high above mountain drainages. Some communities have long houses. Leadership is achieved by a skilled and socially powerful datu who creates alliances in many ways, including marriage. Several area datus would be organized under a higher datu, united in turn under the Sultanate with a Rajah Muda. This structure is gradually giving way to the westernized scheme of provincial government and local councilmen, which places more emphasis on the young and educated. The distinctive ethnic costumes have mostly given way to commercial clothing, with ethnic materials being sold commercially as antiques.