The Celts' origins can be traced back to 500 BC when they lived in northeastern France, southwestern Germany, and Bohemia. In the next century they expanded their area of control to include northern Italy, France, Spain, the British Isles, and parts of Asia Minor.
Within a few centuries, the Carthaninians drove the Celts out of Spain and the Germanic tribes drove them out of the Rhine Valley. The Celts also ceded the majority of their holdings in Europe and the British Isles to the Romans.
However, the Celts managed to keep their distinctive language and customs on what were once the fringe of their domain: Brittany, the Isle of Man, Wales, Ireland, and the Scottish Highlands.
The Celtic language is a branch of the Indo-European languages, which includes two groups: the Cymric or Brythonic (Cornish, Breton, Gaulish, and Welsh) and the Goidelic (Irish Gaelic, Scottish Gaelic and Manx). One readably noticeable distinction between the groups is that where the Goidelic has a 'q' sound (as in the common Gaelic prefix 'Mac' meaning 'son'), the Brythonic has a 'p' sound (Old Welsh 'map').