The “On the Emblems” Treatise as a Valuable Source of the History of Date Clan Emblems

The article analyzes the history of family emblems that belonged to the Date clan, which is described in the “Aide‑Memoirs on the Careful Examination of [Date clan] Emblems” treatise by Confucian scholar Yusa Bokusai (also known as Yuza Jirouzaemon, 1658—1734). It considers the process of creation of this document, its structure and content as well as its value for modern studies on the Japanese family emblems. The main feature of the treatise is a detailed description of the use of each family emblem. Yusa Bokusai comprehensively compared the data from historical documents with artefacts he found and the memories of the eldest vassals and servicemen of the Date clan. Based on results of the comparison, he revealed how changes in the aesthetic preferences of a particular head of the Date clan influenced the status of heraldic symbols, their appearance and use. Moreover, the treatise highlighted a series of issues, related to the study of the emblematic history of the families, that for many centuries owned a large number of emblems. The most important among them are those with a correlation with the emblems' functions and its applying on certain tangible objects, precedents of granting and receiving the emblems and the reflection of these processes in historical documents, the issue of using the suzerain's family emblems by vassals and servicemen.