The Qieyun (Chinese: 切韻/切韵; pinyin: Qièyùn; Wade–Giles: Ch'ieh4-yün4) is a Chinese rime dictionary, published in 601 CE during the Sui Dynasty. The title Qieyun literally means "cutting rimes" referring to the traditional Chinese fănqiè (反切; "reverse-cutting") system of spelling, and is thus translatable as "Spelling Rimes".
Lù Făyán (陸法言; Lu Fa-yen; 581-618 CE) was the chief editor. The Qieyun preface describes how the book originated from discussions with eight of his friends at his home in Cháng'ān, which was the Suì capital.
In the evening, after they had enjoyed their wine, their discussions always turned to phonology. Differences obtained between the pronunciations of the past and the present and different principles of selection were followed by the various authors. … And so we discussed the right and wrong of South and North, and the prevailing and the obsolete of past and present; wishing to present a more refined and precise standard, we discarded all that was ill-defined and lacked preciseness. … And so I grasped my brush, and aided by the light of a candle, I wrote down a draft summary, which eventually was perfected through wide consultation and penetrating research. (tr. Baxter 1992: 35-36)
None of the editors was originally from Chang'an; they were native speakers of differing dialects—five northern and three southern (Norman 1988:25, Baxter 1992:37). According to Lu, Yan Zhitui (顏之推) and Xiao Gai (蕭該), both men originally from the south, were the most influential in setting up the norms on which the Qieyun was based. (Norman 1988:25)
The Qieyun did not directly record Middle Chinese as a spoken language, but rather how Chinese characters should be pronounced. Since this rime dictionary's spellings are the primary source for reconstructing Middle Chinese, linguists have disagreed over what variety of Chinese it recorded. "Much ink has been spilled concerning the nature of the language underlying the Qieyun," says Norman (1988: 24), who lists three points of view. Some scholars, like Bernhard Karlgren, "held to the view that the Qieyun represented the language of Chang'an"; some "others have supposed that it represented an amalgam of regional pronunciations," technically known as a diasystem. "At the present time most people in the field accept the views of the Chinese scholar Zhou Zumo" (周祖謨; 1914-1995) that Qieyun spellings were a north-south regional compromise between literary pronunciations from the Southern and Northern Dynasties.
When classical Chinese poetry flowered during the Tang Dynasty, the Qieyun became the authoritative source for literary pronunciations and it repeatedly underwent revisions and enlargements (see the link below). It was annotated in 677 by Zhāngsūn Nèyán (長孫訥言), revised and published in 706 by Wáng Renxu (王仁煦) as the Kanmiu Buque Qieyun (刊謬補缺切韻; "Corrected and supplemented Qieyun), collated and republished in 751 by Sun Mian (孫愐) as the Tángyùn (唐韻; "Tang rimes"), and eventually incorporated into the still-extant Guǎngyùn and Jíyùn rime dictionaries from the Song Dynasty. Although most of these Tang dictionary redactions were believed lost, some fragments were discovered among the Dunhuang manuscripts and manuscripts discovered at Turpan; and in 1947 a nearly complete manuscript of the 706 edition was found in the Palace Museum.
The structure of the Qieyun would become the model for subsequent rime dictionaries. Entries with each of the four tones filled a separate volume (or two volumes, in the case of the many words of the "level" tone), divided into 193 final rimes (each named by its first character, called the yùnmù 韻目; "rime eye"), and subdivided into homophone groups (each beginning with a fanqie spelling). It contains 16,917 character entries.