Hanzei (Half Payment of Taxes) (半済)
"Hanzei"means that the Muromachi bakufu (Japanese feudal government headed by a shogun) gave the power of collection of half of the customs or taxes on production from manors and lands under the control of the feudal government to the provincial constables. The law that ratified "Hanzei" is called the hanzei law.
"Hanzei" originally meant 'paying half of the tax' and thus meant, at that time, absolving peasants of half of their customs or taxes; however, in the period of the Northern and Southern Courts, "Hanzei" was used to mean that half of the customs or taxes on the manors and lands under the control of the feudal government were submitted to the troops in order for provincial constables to cover military expenditure and provisions locally, and the first hanzei law was enforced by the feudal government in 1352 (Note that "Hanzei" was also used to mean absolving peasants of half of their customs or taxes in the Northern and Southern Courts period and the Muromachi period). After that, the encroachment of provincial constables into the manors and lands under the control of the feudal government accelerated notably, resulting in advent of Shugo-ryogoku system (the system that a Shugo dominates a manor) and Shugo daimyo (Japanese territorial lord as provincial constable).
The oldest hanzei law in existence was published by the Muromachi bakufu in July 1352. At that time, the government allowed provincial constables to requisition half of the taxes from the production of the year to obtain provisions in the midst of a nationwide disturbance (the Kanno Disturbance), aiming at the manors of the Province of Omi (provincial constable: Rokkaku clan), the Province of Mino (provincial constable: Yoriyasu TOKI) and the Province of Owari (provincial constable: Yoriyasu TOKI) all of which were the bloodiest battlefields in the disturbance. The target manors and lands under the control of the feudal government were called "Hyoro-ryosho."
Accordingly, provincial constables of neighboring provinces started seeking approval for the application of "Hanzei," and permission for "Hanzei" spread to the Province of Kawachi (provincial constable: KO no Moronao), the Province of Izumi (provincial constable: the Hosokawa clan), the Province of Iga (provincial constable: Yoshinaga NIKI), the Province of Ise (provincial constable: Yoshinaga NIKKI) and the Province of Shima (provincial constable: Yoshinaga NIKI) by August of the following year.
In 1355, to prevent the spread of the hanzei law, the feudal government exempted provinces in which the disturbance had settled from its application and made the Honjo (lord of the manor) pay half of the customs or taxes to the provincial constable, instead of letting the provincial constable directly collect the customs or taxes from peasants even in the provinces in which the disturbance was still continuing. However, some provincial constables and their subordinate samurais treated the hanzei law as their established right and continued to intervene in the taxes on manors and lands under the control of the feudal government unreasonably. Under the fluid situation in the midst of the continuing disturbance, the feudal government treated the noble class and the temple/shrine class as well as the samurai class, and thus began controlling the abusive use of samurais' hanzei authority in order to protect the authority of the noble class and the temple/shrine class.
In June 1368, the feudal government issued a general hanzei law (the hanzei law of Oan). The law recognized the right of samurais who were employed to serve the provincial constables (hanzei beneficiaries) to divide all customs and taxes on the manors equally with Honjo on a permanent basis, except for customs and taxes on the lands of the Imperial family, temples and shrines, and regent to the emperor. This law strengthened the provincial constables' claim of the right to rule half of the manors and lands under the control of the feudal government, and manors and lands under the control of the feudal government became divided in various regions, and accordingly the interests of provincial constables expanded gradually.
The most noticeable influence of the practice of the hanzei law was that it triggered the first step to demise of manors. Based on the practice of the hanzei law of Oan, provincial constables disfranchised half of the manors and lands under the control of the feudal government virtually, thereby resulting in the gradual demise of manors.
While provincial constables in the Kamakura period simply had military police powers, those in the Muromachi period gradually absorbed the powers of the lords of manors and the kokuga (provincial government offices) as well as the military police powers, based on the interests obtained in "Hanzei." In parallel with that, provincial constables began controlling and governing samurais (called Kokujin) in their own territories. In this way, provincial constables established their authority that could be exerted in their own territories (ryogoku) by taking advantage of the practice of the hanzei law. To distinguish the provincial constables in the Kamakura period from those in the Muromachi period, provincial constables in the Muromachi period are called "Shugo daimyo," the provincial constable feudal lord, and the system in which Shugo daimyo governed their own territories is called Shugo-ryogoku system.