The
Insular Celts are the speakers of
Insular Celtic languages; they comprise all living Celtic languages, and all of the modern
Celtic nations, but the term is mostly used in reference to the peoples of the
British Iron Age prior to the
Roman conquest. The Insular Celtic languages spread throughout the British Isles in the course of the British Iron Age and soon split into the two major groups,
Goidelic in
Ireland and
Brittonic in
Great Britain, corresponding to the population groups of the
Goidels (Gaels) on one hand and the
Britons and the
Picts on the other. The extent to which these peoples ever formed a
distinct ethnic group remains unclear. While there are early records of the
Continental Celtic languages, allowing a comparatively confident reconstruction of
Proto-Celtic, Insular Celtic languages become attested in connected texts only at the end of the
Dark Ages, from around the 7th century AD, by which time they had become mutually incomprehensible.