In 1743, government official E.J. Jessen collected data for a large geographical work about Denmark and Norway, and a questionnaire for the description of local cultural and natural conditions were sent out. For Denmark, the questionnaire contained 40 questions, one of which concerned unusual personal names. The responses are very diverse, but these so-called "Jessen Relations" are a unique and hitherto unused source for the description of personal names in Denmark.
The name material is very varied and show that several names that are now very rare or extinct, have been used, regionally and locally in the 1700s. A few of the reported names seem to be patronyms that have come into use as first names, for example, Melsen, Gudsen, and Aastredsen. Patronyms was the most widespread type of bynames in the general Danish population in the 18th century; at that time, fixed family names were only common in the cities. Therefore, the use of patronyms as first names is a conspicuous phenomenon for that time and none of these names have survived as first names until the present.
In this paper, patronyms used as first names as they are reported in the Jessen Relations will be compared to name information from across Denmark in a census from 1787. The names’ origin, their regional distribution, and their extinction as first names in the following time will be the main topics.