The most famous Celtic shield is the Battersea shield, found in the River Thames at Battersea. Sometimes objects like shields and swords were thrown into rivers as offerings to a god. The Battersea shield is an amazing work of art, the most famous piece of Celtic art ever found in Britain. It is made of bronze and enamel (coloured glass). Originally it had a wooden back, but only the bronze is left now. However, it is too small (77cm high), fragile, and expensive, to have ever been used in battle, and was most probably just an offering.
The Battersea Shield is currently dated by the museum to c.350–50 BC, though later dates up to the early 1st century AD have previously been suggested. A date in the later part of this range is usually preferred,It was dredged from the bed of the River Thames in London in 1857, during excavations for the predecessor of Chelsea Bridge; in the same area workers found large quantities of Roman and Celtic weapons and skeletons in the riverbed, leading many historians to conclude that the area was the site of Julius Caesar’s crossing of the Thames during the 54 BC invasion of Britain, although it is now thought that the shield was a votive offering, which probably predates the invasion.