Shoen (Private Estate) System in Medieval Japan (9th–14th centuries)

Ritsuryō land allotment begins to strain

Under the ritsuryō state, land and taxes were supposed to be centrally managed through a bureaucratic system modeled in part on Tang China. Over time, population growth and limits on available arable land made it harder to keep the equal-field style land and tax system working as designed. These pressures set the stage for new policies that encouraged private development of farmland.

• Britannica