Petrification date
In genealogy, the date of petrification is the day on which the family name was legally established. From that day on, you could only use the family name that was entered as the name in the birth register or church book. From that day on, changes to the family name were only possible under certain conditions. In the genealogy of births before this date, it must be expected that the parents will be found under a completely different family name in the documents. The reason for this was the residence names common in many areas , which tied the name to the residence ( Rhineland ; Westphalia ;Black Forest ), or the patronyms common in Friesland , which changed with every generation. This does not affect minor discrepancies in the spelling of names that were treated by the registrars at their own discretion. Names with “ss” can also be found after the petrification date in the forms “ss”, “sz”, “hs” or “ß” and vice versa. Different petrification dates apply to the individual countries:
- French occupied Rhineland: April 1, 1803
- Prussia : December 7, 1816 (except for the Province of Westphalia , for which a special regulation was issued in 1822 )
- East Frisia : January 1, 1826
- For most of the German states: January 1, 1876