British Iron Age

The British Iron Age is a conventional name used in the archaeology of Great Britain, referring to the prehistoric and protohistoric phases of the Iron-Age culture of the main island and the smaller islands, typically excluding prehistoric Ireland, which had an independent Iron Age culture of its own. The parallel phase of Irish archaeology is termed the Irish Iron Age. The Iron Age is not an archaeological horizon of common artefacts, but is rather a locally diverse cultural phase.

The British Iron Age lasted in theory from the first significant use of iron for tools and weapons in Britain to the Romanisation of the southern half of the island. The Romanised culture is termed Roman Britain and is considered to supplant the British Iron Age. The Irish Iron Age was ended by the rise of Christianity.

The tribes populating the island belonged to a broadly Celtic culture, termed Insular (as opposed to the non-insular Celtic cultures of continental Gaul and Iberia). The Brythonic and Goidelic languages are recognised as forming the Insular Celtic subgroup of the Celtic languages, "Celtic" being a linguistic term without an implication of a lasting cultural unity connecting Gaul with the British Isles throughout the Iron Age.