The Lantingji Xu or Lanting Xu is a famous work of calligraphy by Wang Xizhi, composed in the year 353. Written in semi-cursive script, it is among the best known and often copied pieces of calligraphy in Chinese history. This work began as the preface to a collection of poetry seminal to the Chinese nature poetry movement, but developed a life of its own. The preface describes the event during that year's Spring Purification Festival in which 42 literati, including Xie An and Sun Chuo, were present at a gathering at the Orchid Pavilion near Shaoxing, Zhejiang, at which they to composed poems, played music, and enjoyed wine. The gentlemen engaged in a drinking contest; wine cups were floated down a small winding creek as the men sat along its banks; whenever a cup stopped, the man closest to the cup was required to empty it and write a poem. In the end, twenty-six of the participants composed thirty-seven poems.
The preface consists of 324 Chinese characters in 28 lines. The character zhī (之) appears 20 times, but no two look the same, which is considered one of the features of this work that constitute its calligraphic excellence. This celebrated work of literature also both flows rhythmically and gives rise to several Chinese idioms. That it is a piece of improvisation can be seen from the revisions in the text.
Emperor Taizong of Tang liked Wang Xizhi's calligraphy so much that he ordered a search for the original copy of Lantingji Xu. According to legend, the original copy was passed down to successive generations in the Wang family in secrecy until the monk Zhiyong, dying without an heir, left it to the care of a disciple monk, Biancai. Tang Taizong sent emissaries on three occasions to retrieve the text, but each time Biancai responded that it had been lost. Unsatisfied, the emperor dispatched censor Xiao Yi who, disguised as a wandering scholar, gradually gained the confidence of Biancai and persuaded him to bring out the "Orchid Pavilion Preface." Thereupon, Xiao Yi seized the work, revealed his identity, and rode back to the capital. The overjoyed emperor had it traced, copied, and engraved into stone for posterity. Taizong treasured the work so much that he had the original interred in his tomb after his death. The story of Tang Taizong seizing the Lantingji xu has since been the subject of numerous plays and novels.
Although Wang's original work was lost, numerous tracing copies and other forms of duplications such as rubbings exist in Chinese history. A Tang era copy by Feng Chengsu (馮承素), dated between 627-650, is considered the best of all the subsequent copies. This copy is located in the Palace Museum in Beijing.