Abstract: The belief in Pichang Dawang, the Divine Lord of the Hide Market, initially took the form of a Land Protector in Xianren Enclosed Block of the Eastern Capital, present-day Kaifeng in Henan Province. This cult first appeared in the Song Dynasty, and its name originated from the official Pijiao Ku, the Hide and Horn Warehouse, of the time. The prototype of this belief was bijing, literally wall mirror. Spider species are known for spinning circular white webs on walls, resembling ancient bronze mirrors, and a spider can be Chinese medicine. Devotion to Pichang Dawang spread widely owing to the distinctive siting of the temple for Pichang Dawang and frequent accounts of miraculous cures linked to it. As a result, its role shifted from that of a territorial protector to a specialized god of Chinese medicine. In the early reign of Emperor Huizong, this belief was conferred an official title and incorporated into the state sacrificial system. This rapid development was closely related to multiple factors. These included the imperial court’s political and diplomatic environment. Other factors were reforms in the ritual, music and medical systems, as well as frequent epidemic outbreaks in the capital region during that period.