An imperial estate (patrimonium or res privata)[1] in the Roman Empire it was the "personal property of members of the imperial family, as distinct from property belonging to the Roman state" (ager publicus).
[2] On the Emperor's death, these properties passed to his successor, and not to his private heirs.
The coloni paid the conductor in shares of their crops, and were also obliged to perform other services a few days a year.
Imperial estates might be disposed of through sales or given as gifts, to individuals, to temples, and later to christian churches.
In North Africa in the fifth century, land registers show that he owned around 15–18%.