The Kayan and the Kenyah are the most populous and powerful of the Orang Ulu groups who have lived for centuries in the upper Rejang and, in the northern interior, along the Batang Baram. The Kayan are more numerous, at around forty thousand, while the Kenyah population is around ten thousand (with substantially more Kenyah over the mountains in Kalimantan). Both groups migrated from East Kalimantan into Sarawak roughly six hundred years ago; they were pushed back to the lands they occupy today during the nineteenth century, when Iban migration led to clashes between the groups,
The Kayan and the Kenyah have a fair amount in common: their language, though of the same family as the other Bornean tongues and Malay, has a singsong quality that sounds like Chinese, and they have a well-defined social hierarchy, unlike the Iban or Penan. Traditionally, the social order was topped by the tuai rumah (chief) of the longhouse, followed by a group of three or four lesser aristocrats or payin, lay families and slaves (slavery no longer exists). Both groups take pride in their longhouses, which can be massive.
Artistic expression plays an important role in longhouse culture. The Kayan especially maintain a wide range of musical traditions including the lute-like sape, used to accompany long voice epics. Textiles are woven by traditional techniques in the upriver longhouses, and Kayan and Kenyah woodcarvings, among the most spectacular in Southeast Asia, are produced both for sale and for ceremonial uses. One artist, Tusau Padan, originally from Kalimantan, became much revered. He used mixed media of vibrant colours to create the flowing motifs he applied to painting and textiles – adorning burial poles, longboats and the walls of many Ulu Sarawak chiefs’ homes. Some Kayan still drink potent rice wine, although now that nearly all the communities have converted to Christianity, alcohol is harder to come by.