Joseon royal decree of appointment and related documents

This collection comprises three letters (items 1–3) issued by the Joseon court appointing a Japanese man, Kayashima Mokubei, as a military officer of the kingdom as well as four related documents (items 4–7) detailing the provenance of the previous three. Exchanged during Japan's first invasion of Joseon Korea (1592), they offer insights into the actions of Japanese soldiers who had followed the Mōri clan, daimyo of the Chūgoku region, to Joseon. Dated 1594, Item 1 is a letter appointing Kayashima Mokubei as a military officer of Joseon. Item 2 is a letter sent by Hong Do (Hong I-sang), the magistrate of Gyeongsang Province in southeastern Korea, to Song Chang-se.

He commended Song for contributing to Kayashima’s defection to Joseon, as well as using Kayashima to deliver enemy information. Item 3 is Hong Do’s reply to a letter from Kayashima. Two sources corroborating the context and provenance of these letters are: Chōsen ōchō jitsuroku (Veritable Records of the Joseon Dynasty) and Hagi-han batsuetsu roku (Records of the Distinguished Clans of Hagi Province). Such sources verify the historical significance of this collection.

— Museum description: Kyushu National Museum (CC BY 4.0), via ColBase / Japan Search.