At the start is a first name: "auda"-"wulfa" ("wealth"-"wolf") i.e. "Odolf" - just as Adolf comes from "adel"-wulfa" ("nobility" - "wolf"). Odolf, Oudolf became last names. A bad transcription of "Jan Odolf" gave "Jan Nodolf", and the last name "Nodolf". In my own family there is a original/official document showing "Oliver Nolf crossed Nodolf" dated 1509. So "Nolf" is a contraction of "Nodolf". Transcription in other languages gives e.g. "Noffle" in France, "Nolfe" in the UK, "Nulf/Nulph" in the US. Also "Nolff" and "De Nolf" (The dutch "De" means "The" (Nolf). Not to be confused with the french "de" : "of"(a given place).
There are today about 600 Nolf's originally from North-Western (flemish) Belgium which then spread to the whole country - and about 400 originally in Northen France, which later also spread over the country. These two original territories were one until 1667/68 (war of Devolution). Most awful period of our history: 2 wars at the same time, one: religious (Catholics from occupying Spain against the Protestants/Calvinists) and two: political (France wanting to expand to the North). Add to that regular epidemics of black pest - the last one recorded in history is the one ending in 1668. How did people survive and families prosper ?? All this on a territory about the size of Rhode Island.
Nolf's are spotted in Germany, Switzerland, Austria, The Netherlands, The UK, etc. Also in Brazil (coming from Belgium originally for a railroad project in the 19th).
Close to a thousand Nolf's live in the USA - originally coming all from Pennsylvania. I have sofar failed to trace that emigration from North Belgium and North France to that State and why. The big drive in the 17th was the religious freedom enjoyed in The Netherlands (only bright spot in the then still medieval Europe) and in "New Netherlands" over the ocean, with capital city New Amsterdam, later New York. Was Pennsylvania previously part of New Netherlands ?
Fun note: sofar no "Nodolf's" were found in Europe, while half a dozen were in the USA !
All remarks really welcome. Thank you !
(Important source: "Woordenboek van de familienamen in Belgie en Noord-Frankrijk" by Dr. Frans De Brabandere - ed. Veen Amsterdam/Antwerpen)