I thought I’d pass along this small section from Robert Lacey’s Great Tales from English History, the book so kindly sent to me by Kelly in California:
“The Celts were fearsome in battle, stripping down to their coarse woven undershorts and painting themselves with the greeny-blue dye that they extracted from the arrow-shaped leaves of the woad plant. Woad was the war paint of Albion’s inhabitants, and it is thought to have inspired a name that has lasted to this day. Pretani is the Celtic for painted, or tattooed folk, and Pytheas seems to have transcribed this into Greek as pretanniké, meaning ‘the land of the painted people.’ When later translated into Latin, pretanniké yielded first Pretannia, then Britannia.”
How very interesting! The true, exact nature of the derivation? Who knows, but I like to think that’s how it happened.