Are you sure he was from Germany? Bern is the capital city of Switzerland. I think if Groomburgh is the place, Vurstzburgh the next city and Bern the district, you have to look there.
In Germany is only one little place named Bern, but there are no places arround which are similar to Groomburgh (Grumburg or Krumburg) or Vurstzburgh (Wurstburg or Wuerzburg).
We do have Wuerzburg a big city in Bavaria or Krummburg a little place in Hessen but they are not in the same area.