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Library of Congress Completes Digitization of Yongle Encyclopedia, Largest Reference Work of Pre-Modern Era

Release Date: 09 May 2023
Yongle Encyclopedia

Library of Congress Completes Digitization of Yongle Encyclopedia, Largest Reference Work of Pre-Modern Era
Digitization Increases Accessibility in Attempt to Capture All Human Knowledge

The Library of Congress has completed a yearslong effort to digitize the Yongle Encyclopedia (Yongle dadian 永樂大典), the largest reference work created in pre-modern China, and possibly the world. Digital publication of the 41 volumes held in the Library’s collections provides open access to one of the most extensive attempts in world history to capture the entirety of human knowledge in book form.

The massive work was compiled between 1403 and 1408 for use by Zhu Di — known as the Yongle emperor, after his reign era name — the third emperor of the Ming dynasty (1368-1644). A hand-copied duplicate of the entire manuscript was produced between 1562 and 1567 during the reigns of the Jiajing and Longqing emperors. The original edition was later totally lost.

The encyclopedia represented an ambitious endeavor to record all forms of knowledge known to Chinese civilization at the time of the Yongle emperor’s reign. It was intended to be an easy-to-consult but comprehensive reference work.

Upon completion, the encyclopedia contained 11,095 volumes and 370 million Chinese characters. Less than 4% of the work now survives, around a tenth of which is held in the Library’s Asian Division.

“Yongle Encyclopedia is thought to be among the world's most valuable books,” said Dongfang Shao, chief of the Library’s Asian Division. “Although there have been various efforts to reproduce the content of these 41 volumes housed in the Library, the greatest value and interest in the volumes is in them as unique artifacts of pre-modern Chinese books. The volumes are valued and revered for their high artistic qualities in traditional Chinese book making.”

The Library is one of the first institutions to make an entire major collection of Yongle Encyclopedia volumes freely available online. The 41 volumes in the Library’s collection required significant conservation treatment prior to digitization.

Acquired during the early 20th century through purchase and donation, the Library’s mainly inconsecutive volumes mirror the vast range of topics covered in the entire encyclopedia set: from biographies of emperors and eminent people to bronzes and their inscriptions; from drinking customs and wine rituals to local histories and maps; and from philosophical works, official reports, and treatises on gerontology to ethnic tribal groups, rare Chinese characters, and costume etiquette guidelines observed by the imperial family and government officials.

The Yongle Encyclopedia volumes preserve content from earlier books produced throughout China, many of which disappeared over the ensuing centuries. The encyclopedia is now the only source for studying those lost texts.

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Media Contact: Leah Knobel,

PR 23-046
ISSN 0731-3527

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