Iron Age tribes in Britain
The names of the Celtic Iron Age tribes in Britain were recorded by Roman and Greek historians and geographers, especially Ptolemy. Information from the distribution of Celtic coins has also shed light on the extents of the territories of the various groups that occupied the island. Historiography. The following ethnic names were recorded in the second century A.D. at the earliest. Technically, the Iron Age had by this date finished, and we are into the Roman period. These tribes are not necessarily the same tribes that had been living in the same area throughout the  entire Iron Age. Where evidence is available, it would seem to indicate that the tribes of the Middle Iron Age tended to group together into larger tribal kingdoms during the Late Iron Age. The Belgae and Atrebates share their names with tribes in France and Belgium, which together with Caesar's note that Diviciacus of the Suessiones had ruled territory in Britain suggest this part of the country may have been conquered and ruled from abroad. The Parisii have also been seen as an immigrant group, although this is debated. It has been suggested that it may be possible to  distinguish the distributions of different tribes from their pottery assemblages for the Middle Iron Age. However, no names are available for these tribes (except perhaps "Pretanoi"), and most of the tribes apart from in the South did not use pottery to a significant enough extent for this methodology to be applied to them. These are also not necessarily the names by which the tribes knew themselves; for instance, "Durotriges" may mean "hillfort-dwellers", referring to the fact that hillforts continued to be occupied in this area after they were abandoned elsewhere in Southern Britain. It is unlikely that the Durotriges  themselves considered this their defining characteristic. Further, "Regnenses" is a Latin name meaning "inhabitants of the (client) kingdom".