Shu (Chinese: 蜀; Sichuanese Pinyin: Su2; former romanization: Shuh), also known as Ancient Shu (Chinese: 古蜀) in historiography, was an ancient kingdom in what is now Sichuan Province. It was based on the Chengdu Plain, in the western Sichuan basin with some extension northeast to the upper Han River valley. To the east was the Ba tribal confederation. Further east down the Han and Yangtze rivers was the State of Chu. To the north over the Qinling Mountains was the State of Qin. To the west and south were tribal peoples of little military power.

Sichuan is a province in Southwestern China occupying the Sichuan Basin and Tibetan Plateau between the Jinsha River on the west, the Daba Mountains in the north and the Yungui Plateau to the south. Sichuan's capital city is Chengdu; its population stands at 83 million. Sichuan neighbors Qinghai to the northwest, Gansu to the north, Shaanxi to the northeast, Chongqing to the east, Guizhou to the southeast, Yunnan to the south, and Tibet to the west.