Peoples of Iron Age Britain & Ireland

Before the clans, before the medieval kingdoms, Britain and Ireland were home to dozens of peoples known to us almost entirely through the eyes of outsiders. The Greek geographer Ptolemy, in his Geographia of around AD 150, listed these groups by name and rough position established [ptolemyGeographia] — recording them from the far edge of the classical world, alongside earlier notices in Caesar and Tacitus.

These were not clans

It is worth saying plainly, because much of the web claims the opposite: these Iron Age peoples were not clans, and there is no continuous line of descent from them to the medieval clans or to anyone alive today. They were polities and confederations — some substantial, some barely more than a name on a map. What usually survives is an exonym: a name given by outsiders, filtered through Greek or Latin, and often attested only once probable [pleiades] . We rarely know what these peoples called themselves.

So the honest version of “the tribe my ancestors came from” is this: a name on a Roman-era map, not a bloodline you can trace. That caution is the whole point of this reference.

The peoples

52 peoples recorded for Britain and Ireland in this period, each shown with the actual attested ancient name forms — Greek where the source is Greek — and the span across which the name is attested. Regional grouping is approximate: these are representative points, and territories overlapped and are debated.

Sources & attribution

• [ptolemyGeographia] Ptolemy, Geographia, Book II (c. AD 150) — the Greek geographer’s list of the poleis and peoples of Britain and Ireland. Public domain (ancient text)
• [pleiades] Pleiades: a gazetteer of past places (pleiades.stoa.org). CC BY 3.0 (attribution required) · link

Ancient name forms and locations are derived from Pleiades, used under CC BY 3.0; © Pleiades contributors.