The Xia dynasty was started by Yu the Great.

King yu was the first King/Empoeror of the xia Dynasty

The Shang dynasty came after the Xia dynasty. The Xia dynasty was once thought to be a myth but then they found evidence to support that it really did exist.

According to some of the earliest records of the Shang, the first dynasty was the Xia dynasty. But some historians believe this dynasty is a myth. I think the Xia dynasty really was an existent dynasty however so I would say it is the earliest. It started at about 2000 B.C. and ended at about 1600 B.C.

The Xia dynasty lasted from ca. 2070 BC-ca. 1600 BC.