Rulers on the silk road

Between the 8th and 10th centuries Central Asia was predominantly ruled by the Uighurs, a Turkic people with an Indo-Iranian strain. Their language, which had its own script, was the lingua franca of the region, and even today their old territory is called by the People's Republic of China the Sinkiang Uighur Autonomous Region.

The Uighurs were interested in religion and art, and industrious as farmers (they grew barley and wheat, ploughing with camels). Their chief asset was their great skill in breeding horses. It was to this source that they looked for their wealth, although they also traded in sal ammoniac, precious stones, antelope horns, yaks, and single-humped camels.

The Chinese Empire was an insatiable market for the Uighur horses - the Chinese had to have a strong cavalry, their chief enemies usually being mounted Tatars from the north, and they could not breed their own chargers. Well aware of this, the Uighurs demanded enormous prices - even as much as 40 bales of silk for a single horse. The Chinese, obliged to turn to them for the herds they desperately needed, deeply resented the Uighurs' manner and would speak of them as haughty and insolent Turks.

The prince whose memorial banner we see here, however, looks mild enough, with his long white beard and mortuary bouquet. The portrait was painted on ram (a cloth made from a plant of the same name) and shows him wearing a long, richly girdled robe and an imposing headdress. Brightly painted and weighted at the bottom, it has no ''wrong'' side, and could be put in a conspicuous position in a cave temple, where it would have been given pride of place. German archaeologists discovered it in Khocho, the old Uighurian capital, while working there just before World War I.

When the Uighurian Kingdom flourished, Central Asia held a medley of peoples (as it does now) and was called by many names - among them Chinese Tatary, Chinese Turkistan, and Kashgaria. Turks lived there, and people of Tungusic stock, Tocharians, Ephtalites (the White Huns) and many others, all fighting, trading, occasionally settling in a given area. The Chinese said of them that ''horseback forms the state.'' But it is also true that they sometimes became highly cultured, so that the oasis towns of the Gobi and the Taklamakhan were both beautiful and artistic.

Much of this civilization came about through the activity of the Silk Road, that long passage linking China, and India, Arabia, Bokhara, and Fergana. The missionaries who accompanied this traffic brought with them the faiths they ardently espoused, seeking and making converts, so that up there on the Roof of the World there were in time great numbers of Buddhists, Manichaeans, and even Nestorian Christians.

The progress of these religions was halted in the 10th century by Islam, which penetrated the area and was successful in converting an Uighurian ruler. This faith drove most of the other religions out, and it was after this that the region declined in power and influence.

The prince of this portrait was so fortunate as to escape witnessing the sorrows of this period - he represents the period when his kingdom was at its zenith.