The first census of the population of this country was held on Monday 10 March 1801. Prior this time there was no accurate count of population.
At the time of the Norman Conquest, Lincoln contained about 1,200 dwelling houses, 166 of which were shortly afterwards pulled down to clear a site for the erection of the Castle. According to a moderate computation, this number of houses would give about 6,000 inhabitants. Compare this figure with the 18,000 estimate to live in London at the same: Lincoln was obviously an important centre.
In the reign of Edward the Third, 1345-6, when Lincoln was perhaps in its most flourishing condition, there were in it 407 families assessed to contribute to the support of the war then carried on against France. This number by the same computation will give 2,035 inhabitants : but, as all persons who earned their livelihood by their own " bodily travail, " and not by that of others, or by trade or merchandise, were to be exempt from the payment of this tax, which was a ninth part of their annual income.
The population suffered also another decimation when England was visited by the " Great Plague" or " Black Death," in 1348-9. Little is known of the real extent of its effect in Lincoln, beyond the statements that it was almost deserted by people whose means allowed them to leave it to avoid the risk of contracting the plague.. Of the number of canons and ecclesiastical officialls of the cathedral, only two stayed in the Close.. Lincoln had a similar drop in its population to other towns and cities of England.
When the poll-tax, or head-tax was levied at the start of the reign of Richard II, the number of persons in Lincoln above 14 years of age, who were liable to pay it, were 3,569, making a total population of the City, Close, and Bail, (according to a like computation), of about 5,000 people. But the removal of the staple-trade from Lincoln meant a further reduction in population.
LIncoln was visited by the Sweating Sickness in the sixteenth century and many lives were lost.