After decades of getting nowhere on my Zetterberg ancestry, I got a lead on my great-grandfather's Swedish origins, and signed up for a trial membership on Genline, since his home parish was included. It's been worth it - though I'm suffering eye strain from reading blurry old parish documents in Swedish over a computer screen! But - I've added several generations to my Zetterberg tree!

Anyway, I've tracked my family back to Vadstena in the mid-1700's. The interesting thing is, their name is reported as both Zetterberg and Setterberg (sometimes for the same individual at different times). So I want to recommend that you search for both names when doing research. There's a definite crossover.

Also when we were in Stockholm last month, I noticed that the phone book cross-references both names (i.e., see also: Setterberg).