sentences:  There is little archaeological evidence to support the theory of a large-scale Celtic invasion (or series of invasions), but it is quite possible that small groups of migrants, highly skilled in the art of war and armed with superior iron weaponry, were powerful enough to gain a foothold in the island and eventually succeeded in subjugating or absorbing the pre-Celtic natives; in the 12th century of the Common Era small bands of heavily armed Anglo-Normans did just this, so there is no conceivable reason why it could not also have happened in the pre-Christian era.Iron ores are widely distributed throughout Ireland – one of the country's two richest deposits is to be found in County Wicklow, just a few days' walk from the Dublin region – but there is little archaeological evidence for an urban settlement on the site of the modern city during the Early Iron Age (or Athlone Phase).Excavations at various locations in the region, however, do indicate intermittent occupation at scattered locations throughout this period (e.g.