That history is pretty sparsely understood though, am I correct in that?
I plan someday to read about the Picts. Those people made the most beautiful artworks in stone and metal, just lovely.
They left almost nothing in writing, which is a common problem among known vanished cultures, including those which are known to have been literate (like the Etruscans).
http://www.lib.umt.edu/lang/celtich.htm#Pictish
http://en.wikipedia.org/wiki/Picts