Ichien Chigyo (一円知行)

Ichien Chigyo was a term used during the Japanese Middle Ages to mean that a particular individual has integrated control over lands in complicated and multi-layered relationships of dominance and rights of the Shoen Koryo (public lands and private estates) system. It is also called ichien shinshi, ichien kanrei, or ichien shihai. The term 'ichien' at the time meant entirety or completeness, and lands that were under ichien control were called ichienchi (ichien land), ichienryo (ichien territory), or ichien no sho (ichien manor).

As seen in relationships among honke (head family), ryoke (lord of the manor), kaihatsu-ryoshu (local notable who developed the land), shokan (officer governing shoen), and jito (manager and lord of manor), dominance relationships involving lands and farmers and also relationships involving rights such as land and profit were related to each other in multiple ways; therefore, the Shoen Koryo system of the Middle Ages was extremely complicated. These dominant, right-related relationships were roughly divided into two types. One was called jobun, which was the profit (from nengu (land tax) and kuji (public duties)) generated from land or by farmers, and the other was called shitaji, which was the land under control.

During the Kamakura period, jito made an aggressive attempt to control soen and koryo, and in particular, they focused on acquisition of the right to control shitaji (shitaji-shinshi ken - the right to appropriate land). Jito, then, through shitaji chubun (physical division of the land) and jitouke (the contract system wherein the manor's owner entrusts a jito to manage his manor and pay the customs), not only acquired the shitaji-shinshi ken but also gradually took the right to control jobun (jobun chigyo (right to control the profit)). As described above, some jito acquired both shitaji and jobun to realize ichien control of shoryo (territories).

During the Muromachi period, shugo (provincial constables) had many more rights than jito of the Kamakura period. Through hanzei (the system in the Muromachi period where the Muromachi bakufu allowed shugo to collect half of the taxes from manors and demesnes as military funds), shugo in the Muromachi period realized wider and stronger ichien control of lands than jito of the Kamakura period, and as a result, the Shugo-Ryogoku system (the system wherein a shugo dominates a manor) was established and shugo became shugo daimyo (military governors). During the Sengoku period (period of warring states), sengoku daimyo (daimyo - Japanese territorial lords in the Sengoku period) further developed ichien chigyo. As described above, ichien chigyo was exponentially developed from the end of the Middle Ages.