Daizhou was named after Dai Commandery, which was abolished around the time of its formation, even though Guangwu County, in which Daizhou is located, had not been part of it. The commandery in turn had been named after the former capital of the Baidi Kingdom of Dai, whose name represented a transcription of the native name using the Chinese character , which is pronounced dài in present-day Mandarin but had probably sounded like /*lˤək-s/ in Old Chinese. That city had been in Hebei's Yu County, but it was used for a series of petty states and appanages during the Warring States, Eighteen Kingdoms, and Han which spread the name into Shanxi's Yanmen and Yunzhong Commanderies. This confusion sometimes caused some medieval writers to erroneously conflate locations in Dai Prefecture (like Mount Wutai) with places from the ancient stories concerning the Zhao conquest of the first Dai Kingdom.