The advent of bronze casting

The 3rd and 2nd millennia were marked by the appearance of increasing warfare, complex urban settlements, intense status differentiation, and administrative and religious hierarchies that legitimated and controlled the massive mobilization of labor for dynastic work or warfare. The casting of bronze left the most-evident archaeological traces of these momentous changes, but its introduction must be seen as part of a far-larger shift in the nature of society as a whole, representing an intensification of the social and religious practices of the Neolithic.

A Chalcolithic Period (Copper Age; i.e., transitional period between the Late Neolithic and the Bronze Age) dating to the mid-5th millennium may be dimly perceived. A growing number of 3rd-millennium sites, primarily in the northwest but also in Henan and Shandong, have yielded primitive knives, awls, and drills made of copper and bronze. Stylistic evidence, such as the sharp angles, flat bottoms, and strap handles of certain Qijia clay pots (in Gansu; c. 2250–1900 bce), has led some scholars to posit an early sheet- or wrought-metal tradition possibly introduced from the west by migrating Indo-European peoples, but no wrought-metal objects have been found.

The construction and baking of the clay cores and sectional piece molds employed in Chinese bronze casting of the 2nd millennium indicate that early metalworking in China rapidly adapted to, if it did not develop indigenously from, the sophisticated high-heat ceramic technology of the Late Neolithic potters, who were already using ceramic molds and cores to produce forms such as the hollow legs of the li cooking caldron. Chinese bronze casting represents, as the continuity in vessel shapes suggests, an aesthetic and technological extension of that ceramic tradition rather than its replacement. The bronze casters’ preference for vessels elevated on ring feet or legs further suggests aesthetic links to the east rather than the northwest.

The number, complexity, and size—the Simuwu tetrapod weighed 1,925 pounds (875 kg)—of the Late Shang ritual vessels reveal high technological competence married to large-scale, labor-intensive metal production. Bronze casting of this scale and character—in which large groups of ore miners, fuel gatherers, ceramists, and foundry workers were under the prescriptive control of the model designers and labor coordinators—must be understood as a manifestation, both technological and social, of the high value that Shang culture placed on hierarchy, social discipline, and central direction in all walks of life. The prestige of owning these metal objects must have derived in part from the political control over others that their production implied.

Chinese legends of the 1st millennium bce describe the labors of Yu, the Chinese “Noah” who drained away the floods to render China habitable and established the first Chinese dynasty, called Xia. Seventeen Xia kings are listed in the Shiji, a comprehensive history written during the 1st century bce, and much ingenuity has been devoted to identifying certain Late Neolithic fortified sites—such as Wangchenggang (“Mound of the Royal City”) in north-central Henan and Dengxiafeng in Xia county (possibly the site of Xiaxu, “Ruins of Xia”?), southern Shanxi—as early Xia capitals. Taosi, also in southern Shanxi, has been identified as a Xia capital because of the “royal” nature of five large male burials found there that were lavishly provided with grave goods. Although they fall within the region traditionally assigned to the Xia, particular archaeological sites can be hard to identify dynastically unless written records are found. The possibility that the Xia and Shang were partly contemporary, as cultures if not as dynasties, further complicates site identifications. A related approach has been to identify as Xia an archaeological horizon that lies developmentally between Late Neolithic and Shang strata.