Ancient Picts - Pictish warriors often painted their bodies with a blue dye from a plant called "Woad". The woad would be painted in different shapes, such as animal. They were very fierce fighters, and the Romans feared them. Sometimes Celtic warriors would enter battle wearing nothing but woad and a necklace. This necklace would supposedly hold healing powers.
Boudicca, Celtic warrior queen, lead a major uprising that nearly caused the Romans to retreat from what is now England. She rode into battle on a chariot with her grown daughters fighting at her side.