and by the social differentiation indicated by differences in their grave goods. In the middle Bronze Age, this development seems to have reversed and social differentiation is only detectable again in the late Bronze Age and the Iron Age. Since the northern part of west Siberia was unknown to ancient literate cultures and the ancient inhabitants of this region have left no literary source material themselves, it is very difficult to make detailed statements about their society. In reference to the settled populations of the Wusun, who settled in the Tianshan and Zhetysu, Chinese sources indicate the existence of a king and several nobles. Economy The economy of the sedentary population in prehistoric Siberia was dominated by pastoralism. Cattle were intensively farmed in all cultures, as were sheep and goats. The raising of horses became very significant in western Siberia, particularly with the beginning of the Iron Age. A somewhat different image is given by the finds from the Xiongnu, who had also domesticated pigs and dogs. Hunting and fishing were initially an important supplement, but lost a lot of their significance over time. Based on important tool remains and the possible remains of irrigation systems, a wide use of agriculture has been proposed by many researchers, but other scholars state that remains of cereals and other clear evidence are only found in the southernmost cultures, as remains of the Wusun of the Tianshan and Zhetysu. There, as in the northern parts of the Xiongnu territory, millet was cultivated and traces of wheat and rice have also been found. Millet seeds are also found in graves from Tuva, possibly indicating that a hitherto unknown population of settled agriculturalists, who might have been responsible for the area's metal-working, existed there alongside the horse nomads. From the chalcolithic, ore mining and metallurgy also occurred. This is shown by finds of slag, tools and workshops in various cultural contexts. Religion and funerary practices The burial customs of the sedentary societies were characterised by great variation. In the west Siberian chalcolithic, simple flat graves are found, in which the corpse is laid flat on its back. In the early Bronze Age, kurgans were erected for the first time, whose inhabitants were members of a newly developed warrior class (to judge from the grave goods interred with them) and were not buried in simple pits, but in wooden or stone structures. Already in the middle