Historical Document Collection of Hikone Castle Museum 彦根城博物館展示解説シート（（仮）古文書が語る世界）

The approximately 27,800 documents within the museum collection have been designated Important Cultural Property in recognition of their value for the study of Japanese history. The collection includes materials that show the relationships between individual Ii daimyo and the shogun, as well as records of how the Ii daimyo operated within the Tokugawa government.

Documents collected from various daimyo in the late nineteenth century also provide highly valuable information about the Tokugawa administration in the final decades before it was overthrown. Among these documents are materials recording the business practices of the retainers of the Ii household and the life of the samurai in the castle town. There are also detailed maps of the castle site and the castle town (Hikone City cultural properties), and letters from the powerful hegemon Toyotomi Hideyoshi, the shoguns of the Tokugawa family, daimyo of other domains, and from various other officials. Also included are records and protocols of ceremonies held at Edo Castle and documents relating to various purchases and commissions that reflect the wealth and lifestyle of the daimyo.