Sino-Tibetan metal sculptures of 1260-1450 represented a minor portion of the Buddhist sculptures produced in China and Tibet, yet one that proved to be significant for subsequent forms perceived in each country. For Tibet these works comprised a continuation in the synthesis of foreign constituents with Tibetan Buddhist art, already a composite of Indian, Kashmiri, Nepalese and Central Asian traits combined with native forms. In China the novel features of Tibetan Buddhist sculpture could not be ignored for long. They eventually stimulated fresh inventions by Chinese sculptors. The advent of Mongol rulers in China brought two diverse cultures into proximity. Tibetan Buddhism was sponsored by the Yuan emperors, and stone sculptures in the Tibetan manner were made in the Hang-chou and Peking areas respectively by the late thirteenth and mid-fourteenth centuries. Simultaneously, Chinese artisans were brought to Tibet to build and furnish temples and palaces in the Chinese style. They added a select group of image types to the Tibetan repertory. These forms were echoed in clay sculptures for some Tsang valley temples, although not duplicated in Tibetan bronzes. In Tibet regional schools of artisans decorated temples with wall paintings and clay images. Bronze casting was done by Tibetans, but more often by immigrant Nepalese metalworkers. Unorthodox bronzes appeared in China in the thirteenth and fourteenth centuries. Some were Kuan-yin figures related to the sculptures of Yunnan. Others, Dharmapala types, bore some relationship to the guardians of T'ang China, but displayed the fearsome attributes of Tibet. New themes in Chinese sculpture were introduced in the fourteenth century, while conventional ones were reinterpreted. The Ascetic Sakyamuni in a new guise, and the Potalaka Kuan-yin with Tibetan ornaments can both be linked with the dated works of the Yung-lo era (1403-24). Classic bronzes of imperial manufacture continued with little alteration to the mid-fifteenth century. From that time they were gradually brought into conformity with Chinese tastes and eventually absorbed into the folk idiom. Likewise in Central Tibet the impact of the Yung-lo bronzes can be verified by inscribed pieces of the fifteenth and sixteenth centuries.