It was based on the Chengdu Plain, in the western Sichuan basin with some extension northeast to the upper Han River valley.

Recent archaeological discoveries at Sanxingdui and Jinsha thought to be sites of Shu culture indicate the presence of a unique civilization in this region before the Qin conquest.

Circa 2050–1250 BCE the site of Sanxingdui 40 km north of Chengdu appears to have been the center of a fairly extensive kingdom.

[4] Shu was first mentioned in Shujing as one of the allies of King Wu of Zhou who helped defeat the Shang in 1046 BCE at the Battle of Muye.

[5] However, shortly after Zhou's conquest, it was mentioned in Yizhoushu that a subordinate of King Wu led an expedition against Shu.

According to Chronicles of Huayang, Cancong was the first of the legendary kings and had protruding eyes, while Duyu taught the people agriculture and transformed into a cuckoo after his death.

[4][9] In 666 BCE a man from Chu called Bieling [vi] ("turtle spirit") founded the Kaiming dynasty which lasted twelve generations until the Qin conquest.

A later account states that the Kaiming kings occupied the far south of Shu before travelling up the Min River and taking over from Duyu.

[10] As the state of Chu expanded westward up the Han and Yangtze valleys it pushed the Ba peoples west toward Shu.

About 316 BCE the Marquis of Zu, who held part of the Stone Cattle Road, became involved with Ba and quarreled with his brother, the twelfth Kaiming King.

Sima Cuo proposed that Qin should use its superior army to annex Shu, develop its resources and use the added strength for a later attack eastward.

In 314 BCE the late Kaiming king's son was appointed Marquis Yaotong of Shu to rule in conjunction with a Qin governor.

The conquest had more than doubled Qin's territory and gave it an area safe from the other states except Chu, but the land had to be developed before its taxes could be converted into military strength.

The great Dujiangyan Irrigation System was begun to divert the Min River east to the Chengdu Plain.

When Liu Bang launched his campaign to found the Han dynasty Sichuan was an important supply base.

These campaigns into tribal territory proved more expensive than they were worth and in 126 BCE they were both cancelled to shift resources to the Xiongnu wars in the north.