Oracle bone script is the oldest attested form of written Chinese, dating to the late 2nd millennium BC. Inscriptions were made by carving characters into oracle bones, usually either the shoulder bones of oxen or the plastrons of turtles. The writings themselves mainly record the results of official divinations carried out on behalf of the Late Shang royal family. These divinations took the form of scapulimancy where the oracle bones were exposed to flames, creating patterns of cracks that were then subjected to interpretation. Both the prompt and interpretation were inscribed on the same piece of bone that had been used for the divination itself.
Out of an estimated 150,000 inscriptions that have been uncovered, the vast majority were unearthed at Yinxu, the site of the final Shang capital (modern-day Anyang, Henan). The most recent major discovery was the Huayuanzhuang cache found near the site in 1993. Of the 1,608 Huayuanzhang pieces, 579 bear inscriptions. Each of the last nine Shang kings are named in the inscriptions beginning with Wu Ding, whose accession is variously dated between 1250 and 1200Â BC. Oracle bone inscriptions corresponding to Wu Ding's reign have been radiocarbon dated to 1254â1197Â BC (Âą10 years). Following the overthrow of the Shang by the Zhou dynasty in c.â1046 BC, divination using milfoil became more common; far fewer oracle bone inscriptions are dated to the Western Zhou. No Zhou-era sites with a comparable cache of inscriptions to Yinxu have been found; however, examples from this period appear to be more widespread, having been found near most major population centers. New sites have continued to be discovered since 2000.