h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

According to my albeit limited knowledge on the subject, battlefield heraldic devises were 'invented' so that opposing armies could distinguish their own leaders from the opposition. Armour at the time was pretty standardised, and a method of distinguishing one person from another was neccessary to stop your men killing you, as the armoured fighters all looked alike - hence heraldic devices were painted on shields.

'G'

Interesting idea.

The origins of heraldy are indeed shrouded in mystery. However, armies of uneducated men would not have been expected to recognise every heraldic device of each of the lords on their side. Sometimes, anyone of any importance could be found off the battlefield at a vantage point - especially if they were in succession to the throne.

One theory of heraldic origins comes from the belief that those who were entitled to use heraldry wanted to extend the link between themselves and deities (kings being annointed by God). The use of Pagan symbols (phoenixes, lions, eagles etc) in Christian empires is no new thing and can be seen in the 12th century church at Vezelay in France and the tomb of Pius IV(?) in the Vatican.

Heraldic devices were so jealously guarded that you could be put into prison for using a device that you were not entitiled to. This happened to Buckingham under Henry VIII.