One theory is that the street was named after the nuns who lived in the area in Haderslev until the mid-16th century. However, “Jomfrugang” and “Jomfrusti” are names found in many Danish towns and cities. In Aabenraa, for example, there is also a street named Jomfrugang, in spite of the fact that no nuns are known to have resided in the town. On the other hand, the name is fitting of the neighbourhood frequented by women of easy virtue.
In the Middle Ages, prostitutes were not allowed to wear flashy clothes but had to wear a red and black hat. They also had to live in certain neighbourhoods. In 1683, a new law banned brothels entirely. However, the law did not prohibit prostitution. This law was effective until the early 19th century.
Another theory regarding the name “Jomfrugang” in Haderslev is therefore that it was the town’s “red-light district”. It is generally thought that the Danish place name is used as a slightly ironic term for the place where women of ill repute lived.
So, you can choose whether you want to believe in the “pious” story about the nuns or the slightly more colourful story about the loose women.