This is actually a topic that is discussed a lot. Most danes believe that it means Dan's Field (Den derived from Dan, the name of an early king; mark means field in danish), however there are a...
If you want info on 'imortant' people in Denmark, you need to consult the book 'Kraks BlÄ bog', which corresponds to 'Who's who' in the English language world. Published by Gads Forlag.