A silver seal used for diplomatic documents by the Tokugawa shogunate late in the Edo Period (1603-1868) has been found, the Tokugawa Memorial Foundation said Monday.
The silver seal, or ginin, was used as the 1859 instrument of ratification for the Treaty of Amity and Commerce between Japan and the United States.
According to the foundation, the seal was contained in a box found at a Tokugawa shogunate storehouse in 2017. Measuring 9.2 cm square and 7.8 cm high, the 2.7-kg seal was used by Tokugawa Iemochi and Tokugawa Yoshinobu, who were the 14th and 15th shoguns, respectively. Yoshinobu was the last Tokugawa shogun.
The shogunate ordered seal engraver Masuda Koen to make the item in 1857. It is engraved with the kanji for keibun ibu, meaning an ideal statesman who is skilled in both literary and military arts.
The seal was used for documents to ratify treaties and credential letters, together with the shogun’s signature.
Masashi Iwatate, a curator of the foundation, said that since documents stamped with the silver seal are mainly kept abroad, further research is now likely to take place.
The seal will be displayed at an exhibition to be held at the Niigata Prefectural Museum of History in Nagaoka between Sept. 15 and 30.