In the late Roman Empire and the Early Middle Ages a colonus (plural: coloni) was a tenant farmer. Known collectively as the "colonate", these farmers operated as sharecroppers, paying landowners with a portion of their crops in exchange for use of their farmlands. The coloni'''s tenant-landlord relationship eventually degraded into one of debt and dependence. As a result, the colonus system became a new type of land tenancy, placing the occupants in a state between freedom and slavery. The colonus system can be considered a predecessor of European feudal serfdom. In Italy, much of the agricultural land was leased to tenants. There was a concept in place that allowed the tenants to have tenure on the land, even though they were not the owners. Tax liabilities went with the sales of a land plot, but most of the taxed public land in Italy was leased rather than owned. Therefore, many of the taxes were imposed upon the tenants rather than the land owners. These tenants could also sell and buy leases, which indicates a somewhat flexible and fair property system. According to the Roman courts, agricultural tenants also had rights against landowners who tried to unjustly infringe upon their contracts. This time period indicated a degree of fairness and justice toward the coloni. Originally, a colonus was in a mutual relationship in which a landowner allowed a tenant the use of their land, in return for a portion of the farmed crops. However, under the rule of Emperor Diocletian, there was a reform in the taxation system, which many historians attribute as the cause of the shift in the tenant-landowner relationship. During his reign 284-305 there were several edicts which tied coloni to the land in order to increase land taxes and poll taxes. Diocletian created a complex tax system based on persons as well as a regular census of the people to monitor the empire's population and wealth. The tax rates were computed by complex mathematical formula. The system was distributive, i.e.