Demographic Censuses are the largest project a country's statistical office has to
undertake periodically.
The designation Demographic Censuses comprises three different censuses: the Population Census, the Housing Census and the Building Census. Another census, with an economic nature, is carried out in the light of the latter: the Commercial Premises Census.
Of all three Demographic Censuses, the Population census is unquestionably the most important and the one with the most longstanding tradition.
The first modern population census, considering the person as the unit for analysis, was performed in Spain in 1768 by the Count of Aranda under the rule of Charles III.
Other notable operations were the 1787 Census carried out by Floridablanca and the census performed ten years later by Godoy in times of Charles IV. However, the first series of official censuses commenced in 1857 with the first operation performed by the Kingdom's General Statistics Commission, which was followed shortly by the 1860 census. The following operations were performed in 1877, 1887 and 1897. As of the year 1900, Population Censuses have been performed every ten years without exception.
In all, the Population Census performed taking November 1st 2001 as the reference date is the sixteenth official Census operation performed in Spain.