At this point the march of invention brought a new factor upon the scene. Iron was dug and forged. Men armed with iron entered Britain from the Continent and killed the men of bronze. At this point we can plainly recognise across the vanished millenniums a fellow-being. A biped capable of slaying another with iron is evidently to modern eyes a man and a brother.

On the end of the Bronze Age and start of the Iron Age, Vol I; The Birth of Britain. - A History of the English-Speaking Peoples (1956–58)