The shield is one of the most basic defensive weapons, a hand-held barrier to deflect blows and protect the user from assault. Depictions of shields go back through time to the red hoplite warrior designs on Greek pottery in the 6th and 5th centuries BC.  In Britain, shields were certainly in regular use by the Iron Age (751 BC–AD 42), and their first co-ordinated and highly disciplined use by an army would have occurred during the Roman invasion of AD 43.