Radboud or Radbod (Frisian; Redbad) was the last independent Frisian king, before Frankish rule. He defeated Charles Martel at Cologne. There's still a castle named after him in Medemblik and Radboud University in Nijmegen(both in the Netherlands).
From what I recall of the name Radboud is that it may be used in Dutch history and can be still used in one certain region, the name is not really of actual Dutch origin due to the fact that the Dutch language wasn't created by that time, since it's ancient German from when the Romans conquered Europe, by that time we spoke a different language and it may be created on ancient Dutch soil, it is not a Dutch name at all to be precise. I'm Dutch myself and did not even hear of this name before, to me it almost looked like a more southern name around France, but what I am saying to call it a Dutch name would be inappropriate since almost 90% would not recognise the name other than from a university, it's still used but only in one province of Holland, and has as I was explaining an ancient German history, at that time the Netherlands and Germany where part of one region which spoke around the same language which isn't now. I add that I did not do any long term research around the name, I just happen to see it on the site and wanted to make known what I know of the name.