Holt Mackenzie was an Englishman in the North-Western Provinces of the Bengal Presidency. He devised the Mahalwari system which came into effect in 1822.
Under this system, the revenue collectors were asked to visit villages, inspect the land, measure the fields and record the customs and rights of different groups.
The estimated revenue of each plot within a village was added up to calculate the revenue that each village (mahal) had to pay. This rate of revenue was not fixed and to be revised periodically. The charge of collecting the revenue was given to village headman rather than the zamindar.