The source material for the HSN database consists mainly of the certificates of birth, death and marriage and of the population registers, which aimed for a continuous registration of the composition of households and the whereabouts of each individual.
Almost every certificate of birth, marriage and death ever filed in the Netherlands is still available, as each was made in duplicate. The original remained in the municipality, and the copy was sent to the registry of the county court after the closing of the register on December 31 of each year. The duplicates have been assembled in the provincial archives, at least for the 19th and early 20th centuries.
The certificates used for the HSN database are from the period after 1812. In 1810 French civil law was introduced in the Netherlands as a consequence of the annexation of the Netherlands by the French Empire. The Code Napoléon provided for the standardised recording of vital events in certificates. These certificates served an essential legal function by recording the changes in individual status occuring through birth, marriage, divorce and death.
At varying dates in the course of the year 1811 Dutch municipalities introduced civil registration. In the first decades of the 19th century the rules for registration were not always unambiguous, leading to great local diversity in interpretation.
In 1838 the Dutch Civil Code was introduced and remained valid until 1970, with only small alterations. From 1838 onwards, the certificates show much greater uniformity than in the period 1811 to 1838.
The certificates had to be drawn up in the municipality where the vital event occurred. Three types of persons named in the certificates fulfilled separate and clearly described tasks:
- The registrar
The registrar's function was to record in a prescribed way the content of a declaration. In other words, he was not allowed to make comments or deviate in any other way from his instructions. He could only refuse a declaration when he was completely sure of its falseness. When in doubt, he had to draw up the certificate anyhow before notifying the public prosecutor. The registrars had to be chosen form among the local council, which meant that they were either mayors or councilors. In practice, once a week the registrar signed the certificates drawn up by the town clerks. In 1904 the law was changed, making it possible for other people to become registrars.
- Parties declaring something (informants)
Examples of parties declaring something concerning themselves are a father who gave notice of the birth of his child and a bride and bridegroom who stated their intention to marry. On the other hand, an undertaker declared an event not concerning himself.
The witnesses did not make any declaration themselves. They were chosen by the declarant or by the prospective spouses. The witnesses simply had to be present when the declaration was made in front of the registrar and afterwards, when the certificate was read aloud. In a strict legal sense the witnesses did not bear testimony to the truth of the testimony itself. Yet to a certain extent they were supposed to affirm the contents of a declaration. The registrars were therefore urged to take care that witnesses were friends or relatives of the informants. They could refuse untrustworthy persons. In practice, however, and particularly in the case of birth certificates, the witnesses were frequently either clerks or other municipal officials, or even persons who made a living signing certificates for a small fee. The only requirements for witnesses that they had to be of age and living in the Netherlands. The age of majority was 21 in the period between 1811 and 1838, 23 from 1838 until 1901, and again 21 from 1901 until 1988. An exception was made for married youngsters, because marriage itself conveyed majority. Last but not least, until 1927 women were not allowed to act as witnesses.
The registrars had to note the names, ages, occupations and (actual) municipality of residence of the informants and witnesses. This information provided the correct identification of individuals. The information required for other persons mentioned in certificates was less detailed. For instance, it was not necessary for the registrar to state the age of the parents on a birth certificate.
Two kinds of notes are found in the margins of certificates. The first are corrections of mistakes made in the text. The second and most important ones are made at a later date and make mention of another certificate that affects the content of the present one. For example, in birth certificates one finds mention of a royal decree allowing for a change of surname. In the margin of marriage certificates notes referring to certificates of divorce can be found.