From the outset, the scholars acknowledged that they were unlikely to stretch history all the way back to the fabled Yellow Emperor. Instead they set out to enrich knowledge of three dynasties that they say reigned from about 2070 B.C., the beginning of the reputed Xia Dynasty, to 771 B.C., when the Zhou Dynasty fell. All are believed to have been agricultural societies with elaborate rituals of divination and sacrifice. Evidence for the very existence of a Xia Dynasty remains slender. Though it is mentioned in history books centuries later, the name does not appear on archaeological finds from the period, or even in inscriptions from the centuries that followed its supposed demise.
Some Western scholars feel it remains more legend than fact.
Still, the project takes as already proven the existence of the Xia as a precursor empire to the better-established Shang, pointing to a site uncovered at Erlitou, Henan Province, in 1959 as the probable capital. Today the presumed palace walls at Erlitou lie under farmland. After the site was excavated and documented, it was covered for protection and local farmers moved in. A few hundred yards away, trained villagers dig in a related excavation, and a few yards beyond them, new buildings are being built. The report today concludes that the Xia ruled from around 2070 B.C. to 1600 B.C., though it does not try to date the reign of each Xia ruler.