Zhengyi is best understood not as a new school but as an old one given a new, official consolidation. The Celestial Masters lineage, after its original theocratic state ended in the third century, continued for centuries as a hereditary line of ordained masters, eventually settling at Longhu Shan, the Dragon and Tiger Mountain in Jiangxi province, where generations of the Zhang family held the title of Celestial Master and continued ordaining priests.
Under the Yuan dynasty in the thirteenth century, the imperial court granted this Longhu Shan lineage formal authority over a wide range of regional liturgical and talismanic traditions that had developed independently across China, consolidating them under the name Zhengyi, Orthodox Unity, with the hereditary Celestial Master as its recognised head. This gave China's married, locally based ritual priests, the daoshi who conducted funerals, exorcisms and community festivals in ordinary towns and villages, a single lineage of ordination and textual authority to appeal to, even though their day to day practice varied enormously by region. The Zhang family held the Celestial Master title at Longhu Shan in an unbroken line into the twentieth century, one of the longest continuously claimed hereditary religious offices anywhere.