In the late Roman Empire and the Early Middle Ages a colonus (plural: coloni) was a tenant farmer.
As a result, the colonus system became a new type of land tenancy, placing the occupants in a state between freedom and slavery.
[citation needed] 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, during the reign of Diocletian (284–305), there was a reform in the taxation system, which many historians view as causing the shift in the tenant-landowner relationship.
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 landowner would also need to show proof through two documents, such as a conductionale instrumentum or a conductio (a labor contract),[3] or a copy of the publici census adscriptio (a receipt of his enrollment into the public tax register).
Coloni adscripticii were forced to subject their possessions to the estate owner and were forbidden from removing them from the house without permission.
A laborer was called an "adscript of the soil" (adscriptus glebae) when he could be sold or transferred with the land, as under feudal villeinage and with serfdom in the Russian Empire until 1861.
Tenancy agreements had to be registered in the municipal tax rolls, and had to include the tenant's name, a particular plot of land, and the landowner's name.
The tenant was then added to the tax roll for that specific field and could therefore be identified as part of the chain of responsibility for that parcel of land.
Latifundia were large parcels of land, which specialized in agriculture for export, such as grain, olive oil, and cattle.
The rich Roman landowners preferred rents gathered from free or tied tenants who outnumbered enslaved agricultural workers many times over, hence ptiicoloni and adscripticii.