A farmer was a lessee, or entrepreneur, who farmed a manor for profit, paying a fixed rent, possibly on an annual or short-term basis, to its lord. The majority of such rents recorded in Domesday Book were for sums in excess - often greatly in excess - of the stated value of the estate in 1086, implying that the peasantry were treated particularly harshly to extract the maximum profit from the lease. The Anglo-Saxon Chronicle has a vivid description of how such leases may have been negotiated:
'The king and the chief men loved ... gold and silver, and did not care how sinfully it was obtained provided it came to them. The king sold his land on very hard terms - as hard as he could get. Then came somebody else and offered more than the other had given, and the king let it go to the man who had offered him more. Then came the third and offered still more, and the king gave it into the hands of the man who offered him most of all, and did not care how sinfully the reeves had got it from poor men, nor how many unlawful things they did. But the more just laws were talked about, the more unlawful things were done'.
The majority of these excessive renders are recorded in circuit 1, almost certainly a quirk of data collection by scribes or commissioners. The number of such renders is likely to have been far greater than Domesday records and may well have affected the bulk of the peasantry.
Although all such leases in Domesday Book are post-Conquest, they were often held by Englishmen.
For more information on such farmers, see Reginald Lennard, Rural England, 1086-1135: a study of social and agrarian conditions (1959); and Sally P.J. Harvey, Domesday: Book of Judgement (2013), pages 193-99.