Earliest censuses were taken in 1567, 1676, 1775 (parish census). Contents vary according to the censuses and their purposes. For example, the census of 1793 for the region of South Prussia (area taken by Prussia in the 1793 partition) includes names of adult males and widows, number of people in each household, professions of the householders, but no ages.
In 1772-1773, Prussia conducted a land tax census of all the Polish lands that they acquired in the partition of Poland known as West Prussia. This land tax census, Marburger Auszüge, was for the purpose of finding out the heads of household and a count of family members and taxing the new households. The paper census was held in the Herder Institut, Marburg, Germany. Microfilm copies are held in Scientific Institute, Turin, Poland. The Odessa, Texas Library has acquired a micorfilm copy from Marburg, Germany. Odessa Library created a a digital index of the Polish heads of household ennumerated in the West Prussia land tax census. Anyone can access this index from the Odessa Library collections at : http://www.odessa3.org/collections/land/
The census of 1790–92 for areas of Poznan (Posen) and Kraków includes school-age children as well as adults and has dates of birth, marriage, and death.