History lessons taught us that the ancient Britons had a secret weapon when it came to frightening off invaders. Even Julius Caesar remarked upon it, 'All the Britons dye themselves with woad, which makes them a sky blue colour and thereby more terrible to their enemies'.
The blue dye is found in Northern Europe and now, in the 21st century, it may become economically important again, both as a natural dye for the textile industry and as an alternative crop for hard-pressed farmers. Dilly Barlow has been travelling here and in northern France with Jenny Balfour Paul, the author of a book on woad. Indigo by Jenny Balfour Paul is published by British Museum Press ISBN 0714125504
