The Yongle Encyclopedia or Yongle Dadian is a largely lost Chinese leishu encyclopedia commissioned by the Yongle Emperor of the Ming dynasty in 1403 and completed by 1408. It comprised 22,937 manuscript rolls or chapters, in 11,095 volumes. Fewer than 400 volumes survive today, comprising about 800 chapters (rolls), or 3.5 percent of the original work. Most of it was lost in the 2nd half of the 19th century, in the midst of Western attacks and social unrests. Its sheer scope and size made it the world's largest general encyclopedia until it was surpassed by Wikipedia on September 9, 2007, nearly six centuries later.