Chan Prefecture
Chanzhou or Chan Prefecture was a zhou in Imperial China seated in modern-day Puyang, Henan. It was established in 621 during the Tang dynasty.
In 1106 the Song dynasty elevated the prefecture to a higher status, changing its name to Kaide Prefecture. This name remained until 1142 when it was changed back to Chan Prefecture by the Jin dynasty, who had captured the territory from the Song dynasty. In 1144 it was renamed as Kai Prefecture.