ca. 21st - ca. 16th century B.C.
Though still not scientifically verified, the existence of the Xia Dynasty is believed likely. The dynasty is said to have held power for nearly five centuries, from 2200 B.C. to 1700 B.C., before becoming corrupt and being overthrown by the Shang Dynasty.

The five visible planets--Saturn, Venus, Mercury, Mars, and Jupiter--were believed to be the ministers of Shangdi, the Lord on High. Their conjunction in the predawn sky of February 1953 B.C. was thought to indicate Shangdi's conferral of the right to rule on the Xia Dynasty. This astronmically calculated date, though, differs from the Chinese records.

The Xia Dynasty exists primarily in legend and mythology. Until scientific excavations were made at early bronze-age sites at Anyang, Henan Province, in 1928, it was difficult to separate myth from reality in regard to the Xia. But since then, and especially in the 1960s and 1970s, archaeologists have uncovered urban sites, bronze implements, and tombs that point to the existence of a Xia civilization in the same locations cited in ancient Chinese historical texts.

If the Xia really did exist it would have been contemporaneous with Late Neolithic cultures such as the Henan Longshan Neolithic culture, and marked an evolutionary stage between the Late Neolithic Period and the typical Chinese urban civilization of the Shang Dynasty.