 ornamented portals and glazed-tile paneling.MongolsGenghis Khan (died 1227), the renowned Mongol conqueror, sacked and destroyed Bukhara in 1224, sparing only the 12th-century Kalyan tower, which was used for throwing criminals to their death. The 14th-century Turkic conqueror Timur, however, endowed Samarkand with new glory by building a series of religious monuments widely renowned for their splendour and decorative use of glazed tiles. In the 16th century Bābur, prince of Fergana, coveted Samarkand. Failing to capture it, he chose Kābul as his headquarters for his conquest of India. His tomb there (he died in 1540) is the only visible testimony to the years he spent in the city.Emirate of BukharaAlthough fine-quality pottery decorated with animal, bird, and figural designs was being made in New Nisa in the 15th century, the artistic revival of the Mongol period that Timur had launched in western Turkistan had died out by the 16th century, when the emirate of Bukhara, incorporating much of Sogdiana, was established. Except for gold-thread embroidery and carpet making, in most of Central Asia the visual arts largely stagnated. In Mongolia the conversion of the Buryats to Lamaism in the 18th century brought into their tradition of ornamentation such Tibetan motifs as the lotus, dragon, and lion.In 1882 the emirate of Bukhara was incorporated as a Russian state. This political act had little cultural effect, and European art remained unknown to Central Asians. Traditional indigenous architecture of baked or unbaked brick construction was revived in the 18th century. Carved doors and screens were again produced. Old styles of Islāmic script were combined with arabesques to adorn metalwork. Zoomorphic junctures persisted in the animal designs created by metalworkers and potters alike, although the ornaments (jewelry) worn by nomadic women had become so stylized as to have lost all resemblance to the ancient animal motifs from which they were descended. Openwork remained a feature of much of the jewelry, notably of the necklaces formed of small openwork plaques linked by rings or chains.Following the Russian Revolution, a new phase of art began in the Soviet-controlled regions of Central Asia. Although the Soviet authorities took steps to maintain the existing carpet and textile industries, they encouraged the inclusion of genre scenes and native animals and vegetation. They also founded schools to train artists in the traditions of European art. Pictorial arts are naturalistic in style, conforming with the principles of social realism as defined by the Soviet authorities. The first Buryat-Mongolian Turkmen (Turkic peoples) painter to achieve distinction in this style was Tsyrenzhap Sampilov.Arctic regionsIn the arctic zone of Central Asia, the prehistoric age extends from the 3rd millennium BC to the arrival of Europeans around AD 1800. Knowledge of the region's arts is still very limited, for it is wholly dependent upon the sculptures produced by Eskimos (Eskimo) living on the shores and in the hinterland of Siberia and the Bering Strait. These sculptures are mostly in walrus tusk, though wood and reindeer horn examples also exist. The majority are small in size and worked in the round to form terminal ornaments for utilitarian or ceremonial objects or statuettes. The latter are not provided with bases and thus must have been designed to be carried about. Many of the implements are decorated with incised patterns formed chiefly of lines and dots. As in all early arts, the statuettes and terminal ornaments are largely concerned with hunting or the magical practices of shamanism. The earliest and finest statuettes of which there is knowledge are assigned to the Okvik culture, which some scholars date to the pre-Christian era, but which others assign to its early centuries. Okvik art is concerned primarily with the representation of the human figure, differing in that respect from the contemporary or slightly later Old Bering Sea culture, where interest largely centres on animals, such as reindeer, elks, bears, and seals.Wor