永乐大典

Ordered by the 永乐 Emperor and finished in 1408 under 解缙, it copied whole works by hand into 22,877 scrolls, some 370 million characters, with more than two thousand scholars at work. The original vanished; a copy made in the 1560s was burned and looted in 1860 and 1900, and what is left is scattered over libraries in several countries.

Many books that were otherwise lost survive only as quotations in it: the editors of the 四库全书 copied several hundred of them back out.