[3] Zhangye Commandery was established by Western Han in 111 BC, with the seat at the site of modern Wuwei, Gansu.

The area is on the frontier of China proper, protecting it from the nomads of the northwest and permitting its armies access to the Tarim Basin.

[citation needed] Before being over-run by the Mongols, it was dominated by the Western Xia dynasty, and before by the Uyghurs from at least the early 10th century.

[5] The Yuan dynasty founding emperor Kublai is said to have been born in the Dafo Temple, Zhangye, now the site of the longest wooden reclining Buddha in China.

[citation needed] Marco Polo's journal states that he spent a year in the town during his journey to China.

[3] The pine forests of the Babao Mountains (part of the Qilian range) formerly regulated the flow of the Ruo or Hei Shui, Ganzhou's primary river.

Despite recommendations that they should thus be protected in perpetuity, a Qing dynasty imperial official in charge of erecting the poles for China's telegraph network ordered them cleared in the 1880s.

It takes up the entire breadth of the province, running from Inner Mongolia on the north to Qinghai on the south, but its urban core is at Ganzhou in the oasis formed by the Ruo or Hei River.

Its streams, sunlight, and fertile soil make it an important regional agricultural centre, although it was seriously damaged by over-foresting in the 19th century.