Kashindan

In and before the Kamakura period, the clan head and its members, who were related to the clan head, had one type of a cooperative relationship comparable to that of a kin community. However, during the Nanboku-chō and Muromachi periods, the clan heads began to place their own clan members among the retainers of the clan, and ranked them as their kashin. This gave birth to the distinctive kashidan of the post-Nanboku-chō period samurai institution. During this period, the collective body made up from the lord and the kashindan was called kachū.[2]

In the Sengoku period, the daimyo organized their own kashindan as a standing army in response to the need for a strong military organization with a centralized power structure. In particular, Oda Nobunaga, one of the leading figures of the Sengoku period, organized a professional army by creating a class of full-time samurai soldiers made up of jizamurai and mercenaries, who were removed from their peacetime agriculture. After the 1588 sword hunt ordered by Toyotomi Hideyoshi, and the following heinōbunri policy, a clear distinction between the peasants and the samurai was made, which paved way to a more organized kashindan of the daimyo.[3] This resulted in vast gaps in status between the members of the kashindan, the samurai who had chosen to fight; and the hereditary nanushi (village heads), the samurai who had chosen to farm during the heinōbunri.[4]

During the Edo period, the kashindan became a fixed samurai class, and each samurai family that was in the kashindan of a daimyo, or the shogun, was paid an annual land stipend (chigyō) or rice stipend (fuchimai) according the rank of the family.[1] The kashindan held significant power in relation to the ruler; they made him swear to rule justly, to promote them in accordance to actual merit and to not assassinate them based on the suspicion of treason without telling them beforehand. In exchange to this, the daimyo imposed severe criminal laws with the aim of deterrence, and held the right to make judgements on criminals.[4]

Unlike the Kamakura period kashindan that had deteriorated economically, the kashindan of the Edo period daimyo were economically stable. This was the result of a set of strict laws and social rules on land trade, mortgage and inheritance. It was forbidden to sell land to a fief, and to mortgage it was restricted and only allowed temporarily. Although there were generally no laws regulating inheritance, social rules discouraged the division of heritage, and the obedience from the children and wives to the judgement of the parent was paramount. Generally, the eldest son born of the official wife was presumed to be the heir.[4]

The members of the Tokugawa clan and fudai daimyo were appointed to posts at the top of the ruling structure, such as karō and bugyō. On the other hand, former retainers (kashin) of the local lord class (zaichi ryōshu-sō), who had served under Tokugawa clan, were appointed as tozama daimyo and kunimochi daimyo. Furthermore, the military units were all organized into separate kumi, and the lower-ranked samurai, including the rōtō, chūgen, and komono, were commanded by a kumigashira ("group head").[3]