Not So Secret Secrets: Three Uesugi documents (komonjo) of 1559

Watch Professor Conlan demonstrate how the Uesugi documents were folded and sealed.

These three documents provide a remarkable story. Ashikaga Yoshiteru, a beleaguered Japanese shogun, had received a recipe for gunpowder from an allied warlord, named Otomo Sorin.  This recipe came from the Portuguese, who first landed in Japan in 1542 and was transmitted to Uesugi Kenshin in 1559. It contains an optimal ratio of ingredients and explains how to make gunpowder into a slurry. What is interesting, however, is that this recipe was transmitted in such a way as to be readily readable by all, but the two letters, one by Yoshiteru and the other by Odachi Harumitsu, were carefully sealed. No one could open them without Kenshin knowing about it. These letters are, however, quite banal, and merely served as a way of verifying that this information was from the shogun. Odachi Harumitsu’s letter has similar precautions, but is overall less formal than the shogun’s letter, and treats Uesugi Kenshin with greater respect One can know how these records were folded and presented because the Uesugi documents were preserved in their original format, complete with the cover sheet, which is rarely preserved.

Images and permission provided by the Yonezawa shi Uesugi Hakubutsukan shiryokan