Huanglan

The ''Huanglan'' or ''Imperial Mirror'' was one of the oldest Chinese encyclopedias or ''leishu'' "classified dictionary". Cao Pi, the first emperor of the Wei, ordered its compilation upon his accession to the throne in 220 and it was completed in 222. The purpose of the ''Huanglan'' was to provide the emperor and ministers of state with conveniently arranged summaries of all that was known at the time. Complete versions of the ''Huanglan'' existed until the Song dynasty (960-1279), when it became a mostly lost work, although some fragments did survive in other encyclopedias and anthologies. The ''Huanglan'' was the prototype of the classified encyclopedia and served as a model for later ones such as the (624) Tang ''Yiwen Leiju'' and the (1408) Ming ''Yongle dadian''. Provided by Wikipedia