Pre-literate Iron Age Ireland known mainly through archaeology (ringforts, hillforts like Navan Fort/Emain Macha, La Tene-style metalwork) and later, retrospective early-medieval origin legends rather than contemporary written records.
Gradually gives way to the historically-attested, Christianizing Gaelic Ireland of the early medieval period from around the 4th-5th century CE, the point at which continuous written records and the recognizable tuatha (petty-kingdom) system become documented.
The leading in-print general survey of Iron Age Celtic Europe, covering the peoples and archaeology of Ireland in this period.