In 1959, archaeologist Xu Xusheng led a survey team into the Yiluo Basin near Yanshi, Henan Province, and found what he initially believed to be Bo, the first capital of the Shang dynasty. He was wrong about the dynasty, but right about the significance. The site, named Erlitou after the nearby village, turned out to be the largest settlement of an entire archaeological culture that stretched across Henan and Shanxi, eventually reaching into Shaanxi and Hubei. Most archaeologists now consider it the first state-level society in China -- a place where centralized political authority, monumental architecture, and controlled production of prestige goods first came together.

The site grew through four distinct phases. During Phase I, it was a regional center of about 100 hectares with a population in the low thousands. Urbanization began in Phase II, when the settlement expanded to support roughly 11,000 people. A palatial complex emerged, demarcated by four roads, with a bronze foundry established nearby under elite control. Vehicle tracks found near the palace represent the earliest evidence of wheeled wagons in China. By Phase III, the city reached its peak -- perhaps 24,000 inhabitants living around palaces enclosed by massive rammed-earth walls. Then came Phase IV, when the population declined to around 20,000. Production of bronze and elite goods eventually ceased, the palaces were abandoned, and Erlitou shrank to a village. No evidence of destruction by fire or war has been found. The city simply faded.

Erlitou's most lasting contribution was its bronze technology. While earlier cultures like the Qijia had worked with bronze, Erlitou's output was incomparably more sophisticated and diverse. The culture pioneered the section-mold casting process that would become the hallmark of Chinese bronze production for the next thousand years. Artisans produced tools, musical bells, weapons, and ritual vessels including the earliest known ding -- the three-legged cauldrons that became symbols of political legitimacy. Animal-faced plaques inlaid with turquoise are among the most striking surviving objects. Since there are no copper resources in the Luoyang Plain, the Erlitou people likely acquired their ore from the Zhongtiao Mountains of southern Shanxi, the same region from which they probably obtained salt.

The Erlitou culture occupies the same territory and timeframe that ancient Chinese texts assign to the Xia dynasty, and Chinese archaeologists have generally embraced the identification. The Xia-Shang-Zhou Chronology Project classified all four phases of Erlitou as Xia. But the identification rests on circumstantial evidence. No written records have been found at Erlitou -- symbols on ceramic pieces suggest possible connections to early Chinese characters, but nothing that constitutes proof. Outside China, scholars tend to be more cautious, noting that the absence of contemporary written evidence makes the link unprovable. Archaeological evidence of a massive outburst flood at Jishi Gorge around 1920 BC, shortly before Erlitou's rise, has been proposed as the historical basis for the great flood myth associated with the Xia founder Yu, but this too remains speculative.