An emperor gave Japan's oldest medical book to one physician family, and the author's descendants spent centuries trying to get it back

The court physician Tamba Yasuyori completed the Ishinpō, 30 volumes of medicine, in 984. Most of it quotes Chinese medical books of the Six Dynasties, Sui and Tang periods, many of which are now lost in China. The finest copy is a late Heian manuscript, the oldest surviving complete set. In the Muromachi period the imperial house gave it to the Nakarai family, descendants of the Wake, the Tanba family's rivals in court medicine. One account dates the gift to Emperor Ōgimachi in 1573^†. The Taki family, descendants of Tamba Yasuyori, worked to win it back. At the end of the Edo period they succeeded in borrowing it from the Nakarai. The shogunate's medical academy copied it and carved woodblocks, and a printed edition appeared in 1860. Until then the text had been secret. Letters between the shogunate and the Nakarai about returning the volumes survive with the manuscript. In 1982 the Japanese state bought the Nakarai copy. It was designated a national treasure on 6 June 1984 and is held by the Tokyo National Museum. Part of the set passed into private hands. A second Heian copy, at Ninna-ji temple in Kyoto, is also a national treasure; 5 of its 30 volumes survive.